Update info text in grafana test data source, Fixes #1840

public/app/plugins/datasource/grafana/partials/query.editor.html

@@ -6,12 +6,11 @@
 
 		<p>
 		This is just a test data source that generates random walk series. If this is your only data source
-		open the left side menu and navigate to the data sources admin screen and add your data sources. You can change
-		data source using the button to the left of the <strong>Add query</strong> button.
+		open the left side menu and navigate to the data sources admin screen and add your data sources (you need to be
+		logged in to do this). You can change data source using the button to the left of the <strong>Add query</strong> button.
 		</p>
 	</div>
 	<div class="span2"></div>
 
 	<div class="clearfix"></div>
 </div>
-