Bug 1256314 - Fix twitching of RDM toolbar on startup. r=jryans

MozReview-Commit-ID: GQbdVwfvh1N

devtools/client/themes/responsivedesign.inc.css

@@ -34,7 +34,7 @@
   color: #fff;
   border: 1px solid #111;
   border-radius: 2px;
-  padding: 5px;
+  padding: 0 5px;
   width: 200px;
   margin: 0;
 }