fix(http-client): correct http method for user get
fix(http-client): correct http method for user get

From: https://github.com/camunda/camunda-bpm-sdk-js/issues/7

Related to CAM-4519

camunda/camunda-bpm-sdk-js,camunda/camunda-bpm-sdk-js,nagyistoce/camunda-bpm-sdk-js,lightswitch05/camunda-bpm-sdk-js,nagyistoce/camunda-bpm-sdk-js,lightswitch05/camunda-bpm-sdk-js