fix(menu): labeled right menu icon size

icons inside "right menu" of a "labeled menu" were not properly displayed since #111
As a labeled menu can contain dropdowns with themselves can also contain a right menu, we have to be careful of nested selectors here. That's why i did not simply revert the original patch (and we would need to remove and test losts of !important settings which most probably breaks a lot of other use cases)

src/definitions/collections/menu.less

@@ -1277,6 +1277,7 @@ Floated Menu / Item
     }
 
     /* Icon */
+    .ui.labeled.icon.menu > .right.menu > .item > i.icon:not(.dropdown),
     .ui.labeled.icon.menu > .item > i.icon:not(.dropdown) {
         height: 1em;
         display: block;