Update RCTAgora.m

ios/RCTAgora/RCTAgora.m

     NSMutableDictionary *params = @{}.mutableCopy;
     params[@"type"] = @"onUserOffline";
     params[@"uid"] = [NSNumber numberWithInteger:uid];
+    params[@"reason"] = [NSNumber numberWithInteger:reason];
 
     [self sendEvent:params];
 }