Clarify wording in session request form regarding conflicts with BOFs.

 - Legacy-Id: 17377

Author: Sasha Romijn

ietf/secr/templates/includes/sessions_request_form.html

@@ -50,7 +50,7 @@
                </tr>
                <tr>
                  <td colspan="2">BOF or IRTF Sessions:</td>
-                 <td>Please enter free form requests in the Special Requests field below.</td>
+                 <td>If the sessions can not be found in the fields above, please enter free form requests in the Special Requests field below.</td>
                </tr>
              </table>
            </td>