Fix UninitializedProperty exception

If the socket was not connected, disconnect call raise the exception. Need if statement

Author: Kutashov

app/src/main/java/moe/codeest/rxsocketclientdemo/JavaActivity.java

@@ -133,7 +133,9 @@ public void onClick(View v) {
 
             case R.id.btn_disconnect:
                 //disconnect
-                mClient.disconnect();
+                if (mClient.isConnecting()) {
+                    mClient.disconnect();
+                }
 
                 //or disconnect
 //                ref.dispose();