Fixes #14557: Reset the bottom margin on .form-group:last-child in...

Fixes #14557: Reset the bottom margin on .form-group:last-child in .navbar-form to prevent extra spacing

dist/css/bootstrap.css

@@ -4123,6 +4123,9 @@ select[multiple].input-group-sm > .input-group-btn > .btn {
   .navbar-form .form-group {
     margin-bottom: 5px;
   }
+  .navbar-form .form-group:last-child {
+    margin-bottom: 0;
+  }
 }
 @media (min-width: 768px) {
   .navbar-form {

less/navbar.less

@@ -299,6 +299,10 @@
   .form-group {
     @media (max-width: @grid-float-breakpoint-max) {
       margin-bottom: 5px;
+
+      &:last-child {
+        margin-bottom: 0;
+      }
     }
   }