downgrade <label>-related callouts from danger to warning

docs/components.html

@@ -1432,7 +1432,7 @@ lead: "Over a dozen reusable components built to provide iconography, dropdowns,
       <p>There are some caveats regarding using form controls within fixed elements on mobile devices. <a href="../getting-started/#support-fixed-position-keyboards">See our browser support docs</a> for details.</p>
     </div>
 
-    <div class="bs-callout bs-callout-danger">
+    <div class="bs-callout bs-callout-warning">
       <h4>Always add labels</h4>
       <p>Screen readers will have trouble with your forms if you don't include a label for every input. For these inline navbar forms, you can hide the labels using the <code>.sr-only</code> class.</p>
     </div>

docs/css.html

@@ -1588,7 +1588,7 @@ For example, <code>&lt;section&gt;</code> should be wrapped as inline.
       <h4>Requires custom widths</h4>
       <p>Inputs, selects, and textareas are 100% wide by default in Bootstrap. To use the inline form, you'll have to set a width on the form controls used within.</p>
     </div>
-    <div class="bs-callout bs-callout-danger">
+    <div class="bs-callout bs-callout-warning">
       <h4>Always add labels</h4>
       <p>Screen readers will have trouble with your forms if you don't include a label for every input. For these inline forms, you can hide the labels using the <code>.sr-only</code> class.</p>
     </div>