dgui: remove erroneous `p3d.` prefix (regression from #819)

direct/src/gui/DirectGuiGlobals.py

@@ -70,8 +70,8 @@ B3PRESS = PGButton.getPressPrefix() + MouseButton.three().getName() + '-'
 B1RELEASE = PGButton.getReleasePrefix() + MouseButton.one().getName() + '-'
 B2RELEASE = PGButton.getReleasePrefix() + MouseButton.two().getName() + '-'
 B3RELEASE = PGButton.getReleasePrefix() + MouseButton.three().getName() + '-'
-WHEELUP = PGButton.getReleasePrefix() + p3d.MouseButton.wheelUp().getName() + '-'
-WHEELDOWN = PGButton.getReleasePrefix() + p3d.MouseButton.wheelDown().getName() + '-'
+WHEELUP = PGButton.getReleasePrefix() + MouseButton.wheelUp().getName() + '-'
+WHEELDOWN = PGButton.getReleasePrefix() + MouseButton.wheelDown().getName() + '-'
 # For DirectEntry widgets
 OVERFLOW = PGEntry.getOverflowPrefix()
 ACCEPT = PGEntry.getAcceptPrefix() + KeyboardButton.enter().getName() + '-'