Remove an old workaround (Fixes #2263)

The workaround was added when we were still using OIS for input. It doesn't seem to be needed with SDL.

apps/openmw/mwinput/inputmanagerimp.cpp

@@ -409,8 +409,7 @@ namespace MWInput
 
                 if (mControlSwitch["playerviewswitch"]) {
 
-                    // work around preview mode toggle when pressing Alt+Tab
+                    if (actionIsActive(A_TogglePOV)) {
-                    if (actionIsActive(A_TogglePOV) && !mInputManager->isModifierHeld(SDL_Keymod(KMOD_ALT))) {
                         if (mPreviewPOVDelay <= 0.5 &&
                             (mPreviewPOVDelay += dt) > 0.5)
                         {