Remove unnecessary check (duplicated)

before including the library, it is uselessly checked if the variable __QtAll__ and __InventorAll__ have been defined. The same check is performed again once the library is included

src/Mod/Assembly/Gui/PreCompiled.h

@@ -41,16 +41,12 @@
 #include <boost/core/ignore_unused.hpp>
 
 // Qt
-#ifndef __QtAll__
 #include <Gui/QtAll.h>
-#endif
 
 #include <QWidgetAction>
 
 // all of Inventor
-#ifndef __InventorAll__
 #include <Gui/InventorAll.h>
-#endif
 
 #endif  //_PreComp_