Fix the string for "This file type is not supported" message in the Files app

BUG=141008


Review URL: https://chromiumcodereview.appspot.com/10855242

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@152336 0039d316-1c4b-4281-b951-d872f2087c98

chrome/app/generated_resources.grd

@@ -11586,7 +11586,7 @@ Some features may be unavailable.  Please check that the profile exists and you
       </message>
       <message name="IDS_FILE_BROWSER_NO_ACTION_FOR_FILE" desc="Message shown when user tries to open file, which we can't handle.">
 	      This file type is not supported. Please visit the <ph name="BEGIN_LINK">&lt;a target='_blank' href='$1'&gt;<ex>&lt;a target='_blank' href='$1'&gt;</ex></ph>Chrome Web Store<ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph> to find an app that can open this type of file.
-	      <ph name="BEGIN_LINK">&lt;a target='_blank' href='$2'&gt;<ex>&lt;a target='_blank' href='$2'&gt;</ex></ph>Learn More<ph name="END_LINK">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph>
+	      <ph name="BEGIN_LINK_HELP">&lt;a target='_blank' href='$2'&gt;<ex>&lt;a target='_blank' href='$2'&gt;</ex></ph>Learn More<ph name="END_LINK_HELP">&lt;/a&gt;<ex>&lt;/a&gt;</ex></ph>
       </message>
       <message name="IDS_FILE_BROWSER_ID3_ALBUM" desc="Album">
         Album