doc/developer.xml: change git URIs to GitHub

doc/developer.xml

@@ -97,20 +97,20 @@ Foo(const char *abc, int xyz)
 
     <para>
       MPD sources are managed in a git repository on <ulink
-      url="http://git.musicpd.org/">git.musicpd.org</ulink>.
+      url="https://github.com/MusicPlayerDaemon/">GitHub</ulink>.
     </para>
 
     <para>
       Always write your code against the latest git:
     </para>
 
-    <programlisting>git clone git://git.musicpd.org/master/mpd.git</programlisting>
+    <programlisting>git clone git://github.com/MusicPlayerDaemon/MPD</programlisting>
 
     <para>
       If you already have a clone, update it:
     </para>
 
-    <programlisting>git pull --rebase git://git.musicpd.org/master/mpd.git master</programlisting>
+    <programlisting>git pull --rebase git://github.com/MusicPlayerDaemon/MPD master</programlisting>
 
     <para>
       You can do without "--rebase", but we recommend that you rebase
@@ -188,17 +188,7 @@ Foo(const char *abc, int xyz)
     </para>
 
     <para>
-      <command>git pull</command> requests are preferred.  Regular
-      contributors can get <ulink
-      url="http://git.musicpd.org/account-policy.html">an account on
-      git.musicpd.org</ulink>, but any public git repository will do.
-    </para>
-
-    <para>
-      There is <ulink url="https://github.com/MaxKellermann/MPD">a
-      mirror of the <application>MPD</application> git repository on
-      GitHub</ulink>, and you can use that as well to submit pull
-      requests.
+      <command>git pull</command> requests are preferred.
     </para>
   </chapter>