add note about potential dns cache issue when adding new domain

panel/ui/vdns/zones-zone.html

@@ -31,6 +31,8 @@
     <repeat group="{{ @ns_info_array.defaults_ns_array }}" value="{{ @nameserver }}">
       <b>{{ @nameserver }}</b><br>
     </repeat>
+    Note that if DNS for this domain was just added this could simply be a cache issue.<br>
+    Wait a few minutes and come back to this page to see if the issue clears up.
   </check>
   <check if="{{ @ns_info_array.status=='Error' }}">
     There was an error verifying the Namservers for {{ @ns_info_array.zone }}.<br>