Update httprs for broken range implementations

As discussed in https://gitlab.com/gitlab-org/gitlab-workhorse/issues/168 there
are some Object Storage implementation with broken support for ranged get when
using the header `Range: bytes=0-`.

vendor/github.com/jfbus/httprs/httprs.go

@@ -111,8 +111,15 @@ func (r *HttpReadSeeker) Read(p []byte) (n int, err error) {
 //
 // May return ErrRangeRequestsNotSupported, ErrInvalidRange or ErrContentHasChanged
 func (r *HttpReadSeeker) ReadAt(p []byte, off int64) (n int, err error) {
+	var nn int
+
 	r.Seek(off, 0)
-	return r.Read(p)
+
+	for n < len(p) && err == nil {
+		nn, err = r.Read(p[n:])
+		n += nn
+	}
+	return
 }
 
 // Close closes the response body
@@ -202,7 +209,12 @@ func (r *HttpReadSeeker) rangeRequest() error {
 	case http.StatusRequestedRangeNotSatisfiable:
 		return ErrInvalidRange
 	case http.StatusOK:
+		// some servers return 200 OK for bytes=0-
+		if r.pos > 0 ||
+			(etag != "" && etag != res.Header.Get("ETag")) {
 			return ErrContentHasChanged
+		}
+		fallthrough
 	case http.StatusPartialContent:
 		r.r = res.Body
 		return nil

vendor/vendor.json

@@ -97,10 +97,12 @@
 			"revisionTime": "2017-08-26T09:06:48Z"
 		},
 		{
-			"checksumSHA1": "6TbprMZzwDk+SaW+JxdxvnauyDk=",
+			"checksumSHA1": "mb0MqzDyYEQMgh8+qwVm1RV4cxc=",
 			"path": "github.com/jfbus/httprs",
-			"revision": "32cf48c14a79f94eb3d8100efc00e773c5c8b160",
-			"revisionTime": "2017-11-08T13:45:55Z"
+			"revision": "7861a11508467e8d1575182d6456065e6402d8fc",
+			"revisionTime": "2018-06-14T10:08:21Z",
+			"version": "master",
+			"versionExact": "master"
 		},
 		{
 			"checksumSHA1": "oIkoHb8+rM5Etur5HhZVY/sDQKQ=",