Fix database migration for group_id column

server/database.js

@@ -20,9 +20,7 @@ db.exec(`
     check_interval INTEGER DEFAULT 60000,
     timeout INTEGER DEFAULT 5000,
     enabled INTEGER DEFAULT 1,
-    group_id INTEGER,
-    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
-    FOREIGN KEY (group_id) REFERENCES groups(id) ON DELETE SET NULL
+    created_at DATETIME DEFAULT CURRENT_TIMESTAMP
   );
 
   CREATE TABLE IF NOT EXISTS checks (
@@ -59,7 +57,7 @@ try {
 }
 
 try {
-  db.prepare("ALTER TABLE resources ADD COLUMN group_id INTEGER").run();
+  db.prepare("ALTER TABLE resources ADD COLUMN group_id INTEGER REFERENCES groups(id) ON DELETE SET NULL").run();
 } catch (err) {
   // Column already exists
 }