class13: fix PS1 bash variable in the lab

Author: HappyStoic

classes/class13/Dockerfile

@@ -6,7 +6,7 @@ RUN mkdir -p /var/run/sshd /root/.ssh
 COPY sshd_config /etc/ssh/sshd_config
 
 ENV TERM=xterm-256color
-RUN echo "PS1='\e[92m\u\e[0m@\e[94m\h\e[0m:\e[35m\w\e[0m# '" >> /root/.bashrc && \
+RUN echo "PS1='\[\e[92m\]\u\[\e[0m\]@\[\e[94m\]\h\[\e[0m\]:\[\e[35m\]\w\[\e[0m\]# '" >> /root/.bashrc && \
     echo "export LC_CTYPE=C.UTF-8" >> /root/.bashrc
 
 RUN echo "root:admin" | chpasswd