xmonad: unfuck Gimp save dialogs

...by removing a doFloat.  Things seem normal, minus this, since
(evidently) dialogs are floated by default.  I was getting this horrible
flickering effect before.  In my mind, I added this in the first place
to try to solve that problem, but obviously something has changed.

.xmonad/xmonad.hs

@@ -96,7 +96,6 @@ myKeys x =
 
 myManageHook = composeAll
     [ className =? "Gimp"          --> doFloat
-    , className =? "Quit Gimp"     --> doFloat
     , className =? "Vncviewer"     --> doFloat
     , className =? "Nautilus"      --> doFloat
     , className =? "Svkbd"         --> doFloat