pulseaudio: fix alsa due to alsaLib headers move

The pulseaudio alsa module would fail to load due to missing symbols.

pkgs/servers/pulseaudio/default.nix

@@ -4,6 +4,7 @@
 , avahi, libjack2, libasyncns, lirc, dbus
 , sbc, bluez5, udev, openssl, fftwFloat
 , speexdsp, systemd, webrtc-audio-processing
+, fetchpatch
 
 , x11Support ? false
 
@@ -61,6 +62,18 @@ stdenv.mkDerivation rec {
       ++ lib.optional zeroconfSupport  avahi
     );
 
+    patches = [
+      # The following two patches fix alsalib headers move, remove after the next release
+      (fetchpatch {
+        url = "https://gitlab.freedesktop.org/pulseaudio/pulseaudio/commit/993d3fd89e5611997f1e165bf03edefb0204b0a4.patch";
+        sha256 = "17icnf8026947j1dqw4k16f91vy6zyg7q41zv2j6pxh9fncb1s71";
+      })
+      (fetchpatch {
+        url = "https://gitlab.freedesktop.org/pulseaudio/pulseaudio/commit/b89d33bb182c42db5ad3987b0e91b7bf62f421e8.patch";
+        sha256 = "0jccpc0dgkb0v4xrkyca2pm2k4i6pvahs9bq4hbg34173p23g5nb";
+      })
+    ];
+
   preConfigure = ''
     # Performs and autoreconf
     export NOCONFIGURE="yes"