Merge pull request #1276 from jitsi/respect-disable-rtx

fix: Respect the disableRtx config option.

config.js

@@ -78,5 +78,7 @@ var config = { // eslint-disable-line no-unused-vars
     // edit their profile.
     enableUserRolesBasedOnToken: false,
     // Suspending video might cause problems with audio playback. Disabling until these are fixed.
-    disableSuspendVideo: true
+    disableSuspendVideo: true,
+    // disables or enables RTX (RFC 4588).
+    disableRtx: true
 };