Merge pull request #4824 from M-arcus/patch-1

[BUGFIX] DB: Don't check DNS on IPs

include/dba.php

@@ -52,7 +52,8 @@ class dba {
 		}
 
 		if ($install) {
-			if (strlen($server) && ($server !== 'localhost') && ($server !== '127.0.0.1')) {
+			// server has to be a non-empty string that is not 'localhost' and not an IP
+			if (strlen($server) && ($server !== 'localhost') && filter_var($server, FILTER_VALIDATE_IP) === false) {
 				if (! dns_get_record($server, DNS_A + DNS_CNAME)) {
 					self::$error = L10n::t('Cannot locate DNS info for database server \'%s\'', $server);
 					return false;