Fix MaxWait only configuration

Don't quit when no Items are present after MaxWait passes. Instead, continue and wait for MaxItems or MaxWait to be reached again.

producer.go

@@ -85,7 +85,7 @@ func (p *BatchProducer) WatchProducer() {
 		case <-time.After(p.MaxWait):
 			p.Log.Infoln("MaxWait", "Items=", len(items))
 			if len(items) == 0 {
-				return
+				continue
 			}
 
 			items = p.releaseBatch(items)
@@ -132,4 +132,4 @@ func (p *BatchProducer) createBatchNo() {
 // getBatchNo will get the current BatchNo from the atomic variable.
 func (p *BatchProducer) getBatchNo() int32 {
 	return atomic.LoadInt32(&p.BatchNo)
-}
+}