added qpushbutton forward declare for create gem screen header

Signed-off-by: T.J. Kotha <[email protected]>

Code/Tools/ProjectManager/Source/CreateAGemScreen.h

@@ -15,6 +15,7 @@
 #endif
 
 QT_FORWARD_DECLARE_CLASS(QButtonGroup)
+QT_FORWARD_DECLARE_CLASS(QPushButton)
 QT_FORWARD_DECLARE_CLASS(QDialogButtonBox)
 QT_FORWARD_DECLARE_CLASS(QRadioButton)
 QT_FORWARD_DECLARE_CLASS(QScrollArea)