http: immediately fail streaming uploads instead of spooling them first (see #1614)

http/http.go

@@ -356,6 +356,11 @@ func (f *Fs) Put(in io.Reader, src fs.ObjectInfo, options ...fs.OpenOption) (fs.
 	return nil, errorReadOnly
 }
 
+// PutStream uploads to the remote path with the modTime given of indeterminate size
+func (f *Fs) PutStream(in io.Reader, src fs.ObjectInfo, options ...fs.OpenOption) (fs.Object, error) {
+	return nil, errorReadOnly
+}
+
 // Fs is the filesystem this remote http file object is located within
 func (o *Object) Fs() fs.Info {
 	return o.fs
@@ -479,6 +484,7 @@ func (o *Object) MimeType() string {
 // Check the interfaces are satisfied
 var (
 	_ fs.Fs          = &Fs{}
+	_ fs.PutStreamer = &Fs{}
 	_ fs.Object      = &Object{}
 	_ fs.MimeTyper   = &Object{}
 )