Merge pull request #244 from nhsuk/fix/warning-callout-important

screenreaders should pick up important if the title HAS been changed

Author: pflynny

wagtailnhsukfrontend/templates/wagtailnhsukfrontend/warning_callout.html

@@ -2,7 +2,7 @@
 
 <div class="nhsuk-warning-callout">
   <h{{ heading_level }} class="nhsuk-warning-callout__label" {% add_extra_parameters "title" %}>
-    {% if title == "Important" %}
+    {% if title != "Important" %}
       <span role="text">
         <span class="nhsuk-u-visually-hidden">Important: </span>
         {{ title }}