Fix menu height when switching back from mobile layout

Fixes #2841

public/css/icinga/responsive.less

@@ -67,9 +67,11 @@
   }
 
   #sidebar {
-    top: 0;
+    top: 0 !important;
     height: 32px;
+    padding-bottom: 2.5em;
     width: 100%;
+    z-index: 3;
   }
 
   .dashboard > div.container {

public/js/icinga/ui.js

@@ -600,12 +600,7 @@
                             )
                             .prepend(
                                 $('<div id="mobile-menu-toggle"><button><i class="icon-menu"></i></button></div>')
-                            )
-                            .css({
-                                paddingBottom: $('#mobile-menu-toggle').height(),
-                                top: 0,
-                                zIndex: 3
-                            });
+                            );
                         $search.on('keypress', this.closeMobileMenu);
 
                         this.mobileMenu = true;