Fix keyboard input on MOAP on Linux

This should've been included with the Linux CEF work done last year, but must've gotten left out by mistake. Accidentally tested this patch internally for nearly a year, should be good.

This change makes typing into webpages on media-on-a-prim work, where currently only pasting works to enter text.

indra/newview/llviewermedia.cpp

@@ -2117,6 +2117,9 @@ void LLViewerMediaImpl::focus(bool focus)
 	{
 		// call focus just for the hell of it, even though this apopears to be a nop
 		mMediaSource->focus(focus);
+#if LL_LINUX
+		LLUI::getWindow()->allowLanguageTextInput(NULL, focus);
+#endif
 		if (focus)
 		{
 			// spoof a mouse click to *actually* pass focus