Fixed bug 4024 - remove trailing comma of Controller mappings

because it reports an error "Unexpected controller element"

src/joystick/sort_controllers.py

@@ -20,7 +20,7 @@ def save_controller(line):
     bindings = sorted(match.group(4).split(","))
     if (bindings[0] == ""):
         bindings.pop(0)
-    entry.extend(",".join(bindings) + ",")
+    entry.extend(",".join(bindings))
     entry.append(match.group(5))
     controllers.append(entry)