Update Dockerfile

Dockerfile

@@ -8,9 +8,10 @@ RUN --mount=type=secret,id=VNC_PASSWORD,mode=0444,required=true \
 RUN pwconv
 # RUN apt-add-repository "deb http://download.virtualbox.org/virtualbox/debian $(lsb_release -sc) contrib"# RUN wget -q https://www.virtualbox.org/download/oracle_vbox.asc -O- | sudo apt-key add -
 RUN apt update
-RUN apt-get install software-properties-common -y
-RUN apt-add-repository contrib -y && apt-add-repository non-free -y
-RUN apt update
+# RUN apt-get install software-properties-common -y
+# RUN apt-add-repository contrib -y && apt-add-repository non-free -y
+# RUN apt update
+RUN sed -r -i 's/^deb(.*)$/deb\1 contrib non-free/g' /etc/apt/sources.list
 RUN apt install -y vim bash xfce4-terminal mate-desktop-environment-extras \
     aqemu sudo curl wget aria2 qemu-system-x86 htop chromium screen \
     tigervnc-standalone-server python3-pip python3-websockify \