fix error

Dockerfile

@@ -1,6 +1,7 @@
 FROM centos:latest
 MAINTAINER xiaosong
 RUN yum update -y \
+&& yum swap fakesystemd systemd \
 && yum -y install wget vim tigervnc-server epel-release firefox \
 && yum -y groupinstall xfce
 RUN wget http://fpdownload.macromedia.com/get/flashplayer/pdc/11.2.202.635/install_flash_player_11_linux.x86_64.tar.gz \
@@ -15,4 +16,3 @@ RUN echo "xiaosong" | /usr/bin/vncpasswd -f
 RUN systemctl enable vncserver@:1.service \
 && systemctl start vncserver@:1.service
 EXPOSE 5901
-CMD ["/bin/bash"]