QmlProfilerTool: Don't take empty lines as commands

Change-Id: I4e61eda39c165b175c097e38191ad74a46c64d53
Reviewed-on: http://codereview.qt.nokia.com/3499
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Christiaan Janssen <christiaan.janssen@nokia.com>

src/tools/qmlprofiler/commandlistener.cpp

@@ -45,6 +45,8 @@ void CommandListener::run()
     QTextStream in(stdin, QIODevice::ReadOnly);
     do {
         line = in.readLine();
+        line = line.trimmed();
+        if (!line.isEmpty())
             emit command(line);
     } while (!m_stopRequested && !line.isNull());
 }