fix class name for icon

Author: sereneblue

src/index.html

@@ -79,7 +79,7 @@
 </div>
 </button>
 <button :class="color" class="ui basic top left pointing medium dropdown icon button" data-tooltip="Get coins" data-position="bottom left">
-<i class="large external share icon"></i>
+<i class="large external link icon"></i>
 <div class="menu">
 <div class="divider"></div>
 <div class="header">