set application/x-protobuf content type on auth client

internalsdk/auth/auth.go

@@ -52,7 +52,7 @@ func NewClient(baseURL string, opts *webclient.Opts) AuthClient {
 		httpClient = &http.Client{}
 	}
 	webclient := webclient.NewRESTClient(defaultwebclient.SendToURL(httpClient, baseURL, func(client *resty.Client, req *resty.Request) error {
-		req.SetHeader(common.ContentType, "application/json")
+		req.SetHeader(common.ContentType, "application/x-protobuf")
 		if req.RawRequest.URL != nil && strings.HasPrefix(req.RawRequest.URL.Path, "/users/salt") {
 			// for the /users/salt, we do not need to set any headers so return right away
 			return nil