fix(bybit): pro - changed keepAlive value to 18000, fixes: ccxt#22321

apparently users are still receiving the error after the switch to 19000 ccxt#22321 (comment)

ts/src/pro/bybit.ts

@@ -122,7 +122,7 @@ export default class bybit extends bybitRest {
             },
             'streaming': {
                 'ping': this.ping,
-                'keepAlive': 19000,
+                'keepAlive': 18000,
             },
         });
     }