Clarify error message.

Elasticsearch will throw a 404 if there is no indexes added yet, resulting in
this unclear message -- even for people that are not using any sort of proxy.

This message update should make it easier to quickly troubleshoot why the
the dialogue is popping up.

js/services.js

@@ -90,8 +90,9 @@ angular.module('kibana.services', [])
         alertSrv.set('Error',"Could not contact Elasticsearch at "+config.elasticsearch+
           ". Please ensure that Elasticsearch is reachable from your system." ,'error');
      } else {
-        alertSrv.set('Error',"Could not find "+config.elasticsearch+"/"+indices.join(',')+"/_mapping. If you"+
-          " are using a proxy, ensure it is configured correctly",'error');
+        alertSrv.set('Error',"No index found at "+config.elasticsearch+"/" +
+         indices.join(',')+"/_mapping. Please create at least one index."  +
+         "If you're using a proxy ensure it is configured correctly.",'error');
       }
     });