message: fix the use of concat
diff: @@ -103,11 +103,11 @@ export class SQLToolsLanguageClient implements SQLTools.LanguageClientInterface
  };
  let selector = [];
  if (ConfigManager.completionLanguages){
  - selector.concat(ConfigManager.completionLanguages);
  + selector = selector.concat(ConfigManager.completionLanguages);
  }
  if (ConfigManager.formatLanguages) {
  - selector.concat(ConfigManager.formatLanguages);
  + selector = selector.concat(ConfigManager.formatLanguages);
  }
  selector = selector.reduce((agg, language) => {
  