bug 1281293 increase marionette server listen backlog to 1 r=ato

to accept connections on Linux 4.4.
https://bugzilla.kernel.org/show_bug.cgi?id=119141

MozReview-Commit-ID: B5NMkHiGNg6

--HG--
extra : rebase_source : 1bc9322067ad8c3d2a97dfc86a90a0ad8429344f

testing/marionette/server.js

@@ -88,7 +88,7 @@ MarionetteServer.prototype.start = function() {
   if (this.forceLocal) {
     flags |= Ci.nsIServerSocket.LoopbackOnly;
   }
-  this.listener = new ServerSocket(this.port, flags, 0);
+  this.listener = new ServerSocket(this.port, flags, 1);
   this.listener.asyncListen(this);
   this.alive = true;
 };