Fixed height of issue board blank state

app/assets/stylesheets/pages/boards.scss

-lex
 [v-cloak] {
   display: none;
 }
@@ -132,7 +131,7 @@ lex
 }
 
 .board-blank-state {
-  height: 100%;
+  height: calc(100% - 49px);
   padding: $gl-padding;
   background-color: #fff;
 }