fix review comment

core/src/main/resources/hudson/tasks/ArtifactArchiver/help-artifacts.html

@@ -2,7 +2,7 @@
    You can use wildcards like 'module/dist/**/*.zip'.
    See <a href='http://ant.apache.org/manual/Types/fileset.html'>
    the includes attribute of Ant fileset</a> for the exact format
-   -- except that <tt>" "</tt> (<em>space</em>) is not supported as a separator.
+   -- except that <tt>","</tt> (<em>comma</em>) is the only supported separator.
    The base directory is <a href='ws/'>the workspace</a>.
    You can only archive files that are located in your workspace.
 </div>