fixes #4540: adjust vertical alignment of .btn-group in .navbar

docs/assets/css/bootstrap.css

@@ -4163,7 +4163,7 @@ input[type="submit"].btn.btn-mini {
 
 .navbar .btn,
 .navbar .btn-group {
-  margin-top: 6px;
+  margin-top: 5px;
 }
 
 .navbar .btn-group .btn {

less/navbar.less

@@ -87,7 +87,7 @@
 // -------------------------
 .navbar .btn,
 .navbar .btn-group {
-  .navbarVerticalAlign(28px); // Vertically center in navbar
+  .navbarVerticalAlign(30px); // Vertically center in navbar
 }
 .navbar .btn-group .btn {
   margin-top: 0; // then undo the margin here so we don't accidentally double it