Fix bug in Dockerfile

remove -e flag from echo to not add it to bashrc

Author: balthasarschuess

Dockerfile

@@ -22,7 +22,7 @@ COPY src/ros2_rust/docker/rosidl_rust_setup.sh /
 RUN ./rosidl_rust_setup.sh
 
 RUN mkdir -p /workspace && echo "Did you forget to mount the repository into the Docker container?" > /workspace/HELLO.txt
-RUN echo -e "\nsource /opt/ros/${ROS_DISTRO}/setup.sh" >> /root/.bashrc
+RUN echo "\nsource /opt/ros/${ROS_DISTRO}/setup.sh" >> /root/.bashrc
 WORKDIR /workspace