Remove unnecessary perspective from flip transition

src/definitions/modules/transition.less

@@ -59,7 +59,7 @@
   display: block !important;
   visibility: visible !important;
   backface-visibility: @backfaceVisibility;
-  transform: rotateZ(0deg);
+  transform: rotateZ(0deg) !important;
 }
 
 /* Disabled */

src/themes/default/modules/transition.overrides

@@ -270,7 +270,6 @@
 .flip.transition.in,
 .flip.transition.out {
   animation-duration: 600ms;
-  perspective: 2000px;
 }
 .horizontal.flip.transition.in {
   animation-name: horizontalFlipIn;