Fix "Plus" icon size in dashboard

public/ng/css/gogs.css

@@ -866,7 +866,7 @@ ol.linenums {
   border-top-right-radius: .3em;
 }
 #dashboard-new-repo .octicon {
-  font-size: 2em;
+  font-size: 20px;
 }
 #dashboard-new-repo-menu {
   top: 33px;