manual: Update URLs which give 301.

The link to the discount page is missing a trailing slash. For all
others the URL is redirected permanently to the https variant.

Found by the w3m link checker.

diff --git a/web/manual.md b/web/manual.md
index d7507009fc426f0f2b9d7359e65652640e607625..0d1e758baafbde21720051f65aab3c541b916eb3 100644 (file)
--- a/web/manual.md
+++ b/web/manual.md
@@ -330,7 +330,7 @@ code repository, execute
 
                git clone git://git.tuebingen.mpg.de/osl
 
-- [openssl](http://www.openssl.org/) or
+- [openssl](https://www.openssl.org/) or
 [libgcrypt](ftp://ftp.gnupg.org/gcrypt/libgcrypt/).  At least one
 of these two libraries is needed as the backend for cryptographic
 routines on both the server and the client side. Both openssl and
@@ -349,7 +349,7 @@ ID3 tag support, you willl need the libid3tag development package
 recognized. The mp3 tagger also needs this library for modifying
 (id3v1 and id3v2) tags.
 
-- [ogg vorbis](http://www.xiph.org/downloads/). For ogg vorbis streams
+- [ogg vorbis](https://www.xiph.org/downloads/). For ogg vorbis streams
 you need libogg, libvorbis, libvorbisfile. The corresponding Debian
 packages are called `libogg-dev` and `libvorbis-dev`.
 
@@ -359,10 +359,10 @@ that for some distributions, e.g. Ubuntu, mp4ff is not part of the
 libfaad package. Install the faad library from sources (available
 through the above link) to get the mp4ff library and header files.
 
-- [speex](http://www.speex.org/). In order to stream or decode speex
+- [speex](https://www.speex.org/). In order to stream or decode speex
 files, libspeex (`libspeex-dev`) is required.
 
-- [flac](http://flac.sourceforge.net/). To stream or decode files
+- [flac](https://xiph.org/flac/). To stream or decode files
 encoded with the _Free Lossless Audio Codec_, libFLAC (`libFLAC-dev`)
 must be installed.
 
@@ -373,7 +373,7 @@ installed. Debian package: `libsamplerate-dev`.
 - [alsa-lib](ftp://ftp.alsa-project.org/pub/lib/). On Linux, you will
 need to have the ALSA development package `libasound2-dev` installed.
 
-- [libao](http://downloads.xiph.org/releases/ao/). Needed to build
+- [libao](https://ftp.osuosl.org/pub/xiph/releases/ao/). Needed to build
 the ao writer (ESD, PulseAudio,...).  Debian package: `libao-dev`.
 
 - [curses](ftp://ftp.gnu.org/pub/gnu/ncurses). Needed for
@@ -2007,7 +2007,7 @@ and for getting updates.
 the configure file which is shipped in the tarballs but has to be
 generated when compiling from git.
 
-- [discount](http://www.pell.portland.or.us/~orc/Code/discount). The
+- [discount](http://www.pell.portland.or.us/~orc/Code/discount/). The
 HTML version of this manual and some of the paraslash web pages are
 written in the Markdown markup language and are translated into html
 with the converter of the *Discount* package.
@@ -2111,7 +2111,7 @@ Coding Style
 
 The preferred coding style for paraslash coincides more or less
 with the style of the Linux kernel. So rather than repeating what is
-written [there](http://www.kernel.org/doc/Documentation/process/coding-style.rst),
+written [there](https://www.kernel.org/doc/Documentation/process/coding-style.rst),
 here are the most important points.
 
 - Burn the GNU coding standards.
@@ -2374,17 +2374,17 @@ Application web pages
 ---------------------
 
 - [paraslash](http://people.tuebingen.mpg.de/maan/paraslash/)
-- [xmms](http://xmms2.org/wiki/Main_Page)
+- [xmms](https://xmms2.org/wiki/Main_Page)
 - [mpg123](http://www.mpg123.de/)
-- [gstreamer](http://gstreamer.freedesktop.org/)
+- [gstreamer](https://gstreamer.freedesktop.org/)
 - [icecast](http://www.icecast.org/)
-- [Audio Compress](http://beesbuzz.biz/code/audiocompress.php)
+- [Audio Compress](https://beesbuzz.biz/code/audiocompress.php)
 
 External documentation
 ----------------------
 
 - [The mathematics of
-Raid6](http://kernel.org/pub/linux/kernel/people/hpa/raid6.pdf)
+Raid6](https://www.kernel.org/pub/linux/kernel/people/hpa/raid6.pdf)
 by H. Peter Anvin
 
 - [Effective Erasure Codes for reliable Computer Communication