fix sticky z-index

Resources/public/css/layout.css

@@ -351,7 +351,7 @@ body.fixed .content-header .navbar.stuck {
     top:50px;
     width: 100%;
     margin-left: -15px;
-    z-index: 1;
+    z-index: 5;
     border-radius: 0;
 }
 
@@ -361,7 +361,7 @@ body.fixed .content-header .navbar.stuck {
     width: 100%;
     margin-left: -15px;
     margin-bottom: 0;
-    z-index: 1;
+    z-index: 5;
     border-radius: 0;
 }