One more NullPointerException gone without really knowing how it was …

…even possible...

src/org/pcgod/mumbleclient/app/ChannelList.java

@@ -335,7 +335,8 @@ private void synchronizeControls() {
 		// We used mService.isConnected at some point but this has an issue if
 		// onConnected has not been called yet (and thus visibleChannel has not
 		// been set).
-		if (mService == null || visibleChannel == null) {
+		if (mService == null || mService.getCurrentChannel() == null ||
+			visibleChannel == null) {
 			findViewById(R.id.connectionViewRoot).setVisibility(View.GONE);
 			speakButton.setEnabled(false);
 			joinButton.setEnabled(false);