Update gm_api.ts

Author: cyfung1031

src/app/service/content/gm_api/gm_api.ts

@@ -1409,7 +1409,11 @@ export default class GMApi extends GM_Base {
         error = null; // GC
       };
       const onStart = async (con: MessageConnect) => {
-        if (killConn === null || done) return;
+        if (killConn === null || done) {
+          // already resolved
+          con.disconnect();
+          return;
+        }
         try {
           result = await cb();
         } catch (e) {
@@ -1424,7 +1428,7 @@ export default class GMApi extends GM_Base {
         onDisconnected(); // in case .disconnect() not working
       };
       this.connect("runExclusive", [key]).then((con) => {
-        if (killConn === null) {
+        if (killConn === null || done) {
           // already resolved
           con.disconnect();
           return;