the new version moved UI-editing rights out of sysop and its own group because large wikis may have too big of a non-techy admin community (thousands). It would be pointless for a small wiki like ours.
# Prevent new user registrations except by sysops
$wgGroupPermissions['*']['createaccount'] = false;
+# Since 1.32 MW introduced interface-admin group to separate all UI-related rights. This makes sense for bigger sites,
+# but for OSM it makes more sense to keep group structure simple. Give all interface-admin rights to sysops.
+$wgGroupPermissions['sysop'] = array_merge($wgGroupPermissions['sysop'], $wgGroupPermissions['interface-admin']);
+
# Restrict access to the upload directory
$wgUploadPath = "$wgScriptPath/img_auth.php";
<% end -%>