Fix "firefox float right problem"

js/dropdown-item.jade

@@ -1,7 +1,7 @@
 li.dropdown-item(role='presentation', class=classes, id=id)
   a(role='menuitem')
-    if iconLeft
-      span.icon-left(class=iconLeft)
     if iconRight
       span.icon-right(class=iconRight)
+    if iconLeft
+      span.icon-left(class=iconLeft)
     span.text=text