update workspace dockerfile (#1759)

fix workspace user laradock laravel command not found

workspace/Dockerfile

@@ -610,7 +610,7 @@ RUN if [ ${INSTALL_LARAVEL_ENVOY} = true ]; then \
 # Laravel Installer:
 ###########################################################################
 
-USER root
+USER laradock
 
 ARG COMPOSER_REPO_PACKAGIST
 ENV COMPOSER_REPO_PACKAGIST ${COMPOSER_REPO_PACKAGIST}