Fix the first form multi-part item is not a  "file type part" problem in "ParseUpload()"
Fix the first form multi-part item is not a  "file type part" problem in "ParseUpload()"

hxiaodon/seaweedfs,hxiaodon/seaweedfs,chrislusf/seaweedfs,chrislusf/seaweedfs,k85169336/seaweedfs,k85169336/seaweedfs,chrislusf/seaweedfs,chrislusf/seaweedfs