BUG/MINOR: acl: parser must also stop at comma on ACL-only keywords

Igor at owind reported that "url_reg,lower" does not parse because
find_acl_kw() looks for the parenthesis but not for the comma.
diff --git a/src/acl.c b/src/acl.c
index c4f1934..b04c9df 100644
--- a/src/acl.c
+++ b/src/acl.c
@@ -76,7 +76,8 @@
 }
 
 /* Return a pointer to the ACL keyword <kw>, or NULL if not found. Note that if
- * <kw> contains an opening parenthesis, only the left part of it is checked.
+ * <kw> contains an opening parenthesis or a comma, only the left part of it is
+ * checked.
  */
 struct acl_keyword *find_acl_kw(const char *kw)
 {
@@ -84,9 +85,9 @@
 	const char *kwend;
 	struct acl_kw_list *kwl;
 
-	kwend = strchr(kw, '(');
-	if (!kwend)
-		kwend = kw + strlen(kw);
+	kwend = kw;
+	while (*kwend && *kwend != '(' && *kwend != ',')
+		kwend++;
 
 	list_for_each_entry(kwl, &acl_keywords.list, list) {
 		for (index = 0; kwl->kw[index].kw != NULL; index++) {