Remove S3 region is media hostname before matching the media domain

Author: norkans7

Diff for: backends/rapidpro/backend.go

@@ -679,7 +679,7 @@ func (b *backend) ResolveMedia(ctx context.Context, mediaUrl string) (courier.Me
 	mediaUUID := uuidRegex.FindString(u.Path)
 
 	// if hostname isn't our media domain, or path doesn't contain a UUID, don't try to resolve
-	if u.Hostname() != b.config.MediaDomain || mediaUUID == "" {
+	if strings.Replace(u.Hostname(), fmt.Sprintf("%s.", b.config.S3Region), "", -1) != b.config.MediaDomain || mediaUUID == "" {
 		return nil, nil
 	}