iOS: keep keyboard rect in sync

If you resign/become first responder several times
while the keyboard is animating (e.g changing focus between
focus objects while the keyboard is animating), iOS will
short-cut the whole animation, and jump directly to
keyboard end-state. For that reason, we always need to handle
keyboardRectChanged, and not bail out early. This is
fine, since the guard we had was really only meant for
keyboardWillShow/Hide in the first place.

Change-Id: I3a3d1e7061962286c538360029ed38410dc0f347
Reviewed-by: Morten Johan Sørvig <morten.sorvig@digia.com>

src/plugins/platforms/ios/qiosinputcontext.mm

@@ -145,9 +145,6 @@
 - (void) keyboardDidChangeFrame:(NSNotification *)notification
 {
     Q_UNUSED(notification);
-    if (m_ignoreKeyboardChanges)
-        return;
-
     [self handleKeyboardRectChanged];
 
     // If the keyboard was visible and docked from before, this is just a geometry