Bug 1581204 - Remove unused DTDs from mobile, part2. r=snorp

Differential Revision: https://phabricator.services.mozilla.com/D45910

--HG--
extra : moz-landing-system : lando

mobile/locales/en-US/overrides/netError.dtd

@@ -77,15 +77,6 @@
 <!ENTITY notCached.longDesc "<p>The requested document is not available in &brandShortName;’s cache.</p><ul><li>As a security precaution, &brandShortName; does not automatically re-request sensitive documents.</li><li>Click Try Again to re-request the document from the website.</li></ul>">
 
 <!ENTITY netOffline.title "Offline mode">
-<!-- LOCALIZATION NOTE (netOffline.longDesc3) This string contains markup including widgets enabling wifi connections.
-     The text inside the tags should be localized. Do not touch the ids. -->
-<!ENTITY netOffline.longDesc3 "
-<ul>
-  <li>Try again. &brandShortName; will attempt to open a connection and reload the page.
-    <button id='wifi'>Enable Wi-Fi</button>
-  </li>
-</ul>
-">
 
 <!ENTITY contentEncodingError.title "Content Encoding Error">
 <!ENTITY contentEncodingError.longDesc "