ui(gallery): no margin on close & reload button

Change-Id: I728a5d54467232d37f64000db7a8a9f2dab217aa

Author: andi34

src/sass/partials/_gallery.scss

@@ -105,6 +105,7 @@
   width: 2em;
   height: 2em;
   line-height: 1em;
+  margin: 0;
   span {
     display: none;
   }