fix responsive navbar

less/navbar.less

@@ -16,7 +16,7 @@
 
 // Gradient is applied to it's own element because overflow visible is not honored by IE when filter is present
 .navbar-inner {
-  height: @navbarHeight;
+  min-height: @navbarHeight;
   padding-left:  20px;
   padding-right: 20px;
   #gradient > .vertical(@navbarBackgroundHighlight, @navbarBackground);

less/responsive-navbar.less

@@ -112,7 +112,7 @@
   }
 
   // Hide everything in the navbar save .brand and toggle button */
-  .nav-collapse {
+  .nav-collapse, .nav-collapse.collapse {
     overflow: hidden;
     height: 0;
   }
@@ -128,4 +128,4 @@
     height: auto !important;
     overflow: visible !important;
   }
-}
+}