Restore old log timestamp format.

Qt changed the meaning of the format we
were using for the timstamp. Switch back
to Qt:TextFormat which always is HH:MM:SS

Fixes #1332

src/mumble/Log.cpp

@@ -489,7 +489,7 @@ void Log::log(MsgType mt, const QString &console, const QString &terse, bool own
 		} else if (! g.mw->qteLog->document()->isEmpty()) {
 			tc.insertBlock();
 		}
-		tc.insertHtml(Log::msgColor(QString::fromLatin1("[%1] ").arg(Qt::escape(dt.time().toString(Qt::DefaultLocaleShortDate))), Log::Time));
+		tc.insertHtml(Log::msgColor(QString::fromLatin1("[%1] ").arg(Qt::escape(dt.time().toString())), Log::Time));
 		validHtml(console, true, &tc);
 		tc.movePosition(QTextCursor::End);
 		g.mw->qteLog->setTextCursor(tc);