EAGLESIX-2651: add missing call to reset() in AddToSet

lib/pipeline/accumulators/AddToSetAccumulator.js

@@ -9,6 +9,7 @@
 **/
 var AddToSetAccumulator = module.exports = function AddToSetAccumulator(){
 	if (arguments.length !== 0) throw new Error("zero args expected");
+	this.reset();
 	base.call(this);
 }, klass = AddToSetAccumulator, Accumulator = require("./Accumulator"), base = Accumulator, proto = klass.prototype = Object.create(base.prototype, {constructor:{value:klass}});