Bug 1611718 - Retain the about:logins search bar position when the branding is not official r=MattN

Differential Revision: https://phabricator.services.mozilla.com/D61092

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

browser/components/aboutlogins/content/aboutLogins.css

@@ -71,7 +71,7 @@ login-item {
 }
 
 :root:not(.official-branding) #branding-logo {
-  display: none;
+  visibility: hidden;
 }
 
 :root:not(.master-password-auth-required) #master-password-required-overlay {