'Locale not recognized' error when trying to connect via db client

[ademilhan041]

I'm trying to connect the oracle db via DBeaver client. I filled db information as you said and added ojdbc8 as a driver. When I test connection, I get 'Locale not recognized' error.

hostname: localhost
port: 49161
sid: xe
username: system
password: oracle

To fix this, I created new image as in below:

# Dockerfile
FROM wnameless/oracle-xe-11g

RUN apt-get clean && apt-get update && apt-get install -y locales
RUN sed -i -e 's/# en_US.UTF-8 UTF-8/en_US.UTF-8 UTF-8/' /etc/locale.gen && locale-gen
ENV LANG en_US.UTF-8  
ENV LANGUAGE en_US:en  
ENV LC_ALL en_US.UTF-8 

But still I get same error. Do someone know why?