Bug 1533206 - Center the login autocomplete footer text. r=jaws

Differential Revision: https://phabricator.services.mozilla.com/D23395

--HG--
extra : histedit_source : d25b3ee35de5da8a67f47b9a8aebcc129c3bab04

browser/base/content/browser.css

@@ -717,8 +717,8 @@ html|input.urlbar-input {
 }
 
 #PopupAutoComplete > richlistbox > richlistitem[originaltype="loginsFooter"] {
+  -moz-box-pack: center;
   color: var(--btn-text-color);
-  padding: 0 20px;
   min-height: 40px;
   border-top: 1px solid rgba(38,38,38,.15);
   background-color: #EDEDED;