Update Dockerfile (#327)

Author: JimiPedros

Dockerfile

@@ -30,4 +30,5 @@ RUN locale-gen en_US.UTF-8
 # We unfortunately cannot use update-locale because docker will not use the env variables
 # configured in /etc/default/locale so we need to set it manually.
 ENV LANG=en_US.UTF-8
+ENV LC_ALL=en_US.UTF-8 
 ENTRYPOINT ["code-server"]