Fix wrong data initialization in selectivity

if (this.data) {
          options.data = this.data;
        } else {
          options.query = function(query) {
            if (query.term.length < this.minChars) {
              query.error("Please enter " + this.minChars + " or more character");
              return;
            }
            // debounce requests
            this.debounce('_selectivityQuery', function() {
              this._query(query);
            }.bind(this), 300);
          }.bind(this);
        }