signal-desktop-beta: 6.2.0-beta.2 -> 6.3.0-beta.1

It appears that signal forked ringrtc within this release, so until they
merge their changes upstream, or the stable release follows suit, we
have another delta we need to inject and track.

pkgs/applications/networking/instant-messengers/signal-desktop/default.nix

@@ -6,7 +6,8 @@
   };
   signal-desktop-beta = {
     dir = "Signal Beta";
-    version = "6.2.0-beta.2";
-    hash = "sha256-NVwX2xG8QGVjENy6fSA13WQyTlYuF5frcS3asDDg4Ik=";
+    ringrtcPrefix = "@signalapp/";
+    version = "6.3.0-beta.1";
+    hash = "sha256-cYJWhnyiWULnIZvI2/k1koLCd2zrL4CVMohcnSZa/TY=";
   };
 }

pkgs/applications/networking/instant-messengers/signal-desktop/generic.nix

@@ -1,5 +1,6 @@
 { pname
 , dir
+, ringrtcPrefix ? ""
 , version
 , hash
 , stdenv
@@ -160,7 +161,7 @@ stdenv.mkDerivation rec {
       --replace "/opt/${dir}/${pname}" $out/bin/${pname}
 
     autoPatchelf --no-recurse -- "$out/lib/${dir}/"
-    patchelf --add-needed ${libpulseaudio}/lib/libpulse.so "$out/lib/${dir}/resources/app.asar.unpacked/node_modules/ringrtc/build/linux/libringrtc-x64.node"
+    patchelf --add-needed ${libpulseaudio}/lib/libpulse.so "$out/lib/${dir}/resources/app.asar.unpacked/node_modules/${ringrtcPrefix}ringrtc/build/linux/libringrtc-x64.node"
   '';
 
   # Tests if the application launches and waits for "Link your phone to Signal Desktop":