list permissive in supported controls (ITS#3453)

servers/slapd/back-bdb/init.c

@@ -582,6 +582,9 @@ bdb_back_initialize(
 		LDAP_CONTROL_SUBENTRIES,
 #endif
  		LDAP_CONTROL_VALUESRETURNFILTER,
+#ifdef LDAP_CONTROL_X_PERMISSIVE_MODIFY
+		LDAP_CONTROL_X_PERMISSIVE_MODIFY,
+#endif
 		NULL
 	};
 

servers/slapd/back-ldbm/init.c

@@ -32,6 +32,9 @@ ldbm_back_initialize(
 	static char *controls[] = {
 		LDAP_CONTROL_MANAGEDSAIT,
 		LDAP_CONTROL_VALUESRETURNFILTER,
+#ifdef LDAP_CONTROL_X_PERMISSIVE_MODIFY
+		LDAP_CONTROL_X_PERMISSIVE_MODIFY,
+#endif
 		NULL
 	};