Fix tag transition

src/definitions/elements/label.less

@@ -196,6 +196,7 @@ a.ui.label {
   padding-right: @tagHorizontalPadding;
 
   border-radius: 0em @borderRadius @borderRadius 0em;
+  transition: @tagTransition;
 }
 .ui.tag.labels .label:before,
 .ui.tag.label:before {

src/themes/default/elements/label.variables

@@ -123,7 +123,7 @@
 @tagTriangleTopOffset: 50%;
 @tagTriangleSize: 1.56em;
 @tagTriangleBackgroundImage: none;
-@tagTransition: background @labelTransitionDuration @labelTransitionEasing;
+@tagTransition: none; /* Avoids error with background: inherit; on animation */
 
 /* Ribbon */
 @ribbonTriangleSize: 1.2em;