schema/pgsql: allow to delete import sources...

...with history import runs

fixes #11972

schema/pgsql-migrations/upgrade_111.sql

@@ -0,0 +1,11 @@
+ALTER TABLE import_run
+ DROP CONSTRAINT import_run_source,
+ ADD CONSTRAINT import_run_source
+  FOREIGN KEY (source_id)
+  REFERENCES import_source (id)
+  ON DELETE CASCADE
+  ON UPDATE RESTRICT;
+
+INSERT INTO director_schema_migration
+  (schema_version, migration_time)
+  VALUES (111, NOW());

schema/pgsql.sql

@@ -1545,4 +1545,4 @@ CREATE UNIQUE INDEX notification_inheritance ON icinga_notification_inheritance
 
 INSERT INTO director_schema_migration
   (schema_version, migration_time)
-  VALUES (110, NOW());
+  VALUES (111, NOW());