QtSupport: Remove unused CustomExecutableRunConfiguration member

Change-Id: I9f5e7af3767d1a92c0e2104ca56bdb9d0b99f33b
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>

src/plugins/qtsupport/customexecutablerunconfiguration.h

@@ -102,7 +102,6 @@ private:
 
     QString m_executable;
     QString m_workingDirectory;
-    ProjectExplorer::ApplicationLauncher::Mode m_runMode;
     QWidget *m_dialog;
 };