use class="setting-help" in radioBlock.jelly

All other places use this class for a td with help icon.
This improves rendering of the different strategies under "Restrict
project naming"

core/src/main/resources/lib/form/radioBlock.jelly

@@ -63,7 +63,7 @@ THE SOFTWARE.
       </label>
     </td>
     <j:if test="${attrs.help!=null}">
-      <td>
+      <td class="setting-help">
         <a href="#" class="help-button" helpURL="${rootURL}${help}"><img src="${imagesURL}/16x16/help.png" alt="Help for feature: ${title}" height="16" width="16" /></a>
       </td>
     </j:if>