Fix connection bug

TODO: We really should do something better about informing the user of
connection errors and the like.

Persephone/MPDClient/Extensions/MPDClient+Connection.swift

@@ -40,7 +40,9 @@ extension MPDClient {
     let commandOperation = BlockOperation() { [unowned self] in
       self.sendCommand(command: .connect, userData: ["host": host, "port": port])
 
-      self.idle()
+      if self.isConnected {
+        self.idle()
+      }
     }
     commandQueue.addOperation(commandOperation)
   }