Add missing close button on Shortcuts help window

web/css/styles.min.css

@@ -3404,6 +3404,9 @@ form#vstobjects.suspended {
 .shortcuts .close:active {
   background-color: #55c9c0;
 }
+.shortcuts .close .fas {
+  font-size: 1.3rem;
+}
 .shortcuts ul {
   list-style-type: none;
   padding: 30px 20px;

web/templates/footer.html

@@ -7,7 +7,9 @@
   <div class="shortcuts animated fadeIn" style="display:none">
     <div class="header">
       <div class="title"><?=__('Shortcuts')?></div>
-      <div class="close"></div>
+      <div class="close text-center">
+        <i class="fas fa-times"></i>
+      </div>
 
     </div>
     <ul>