do not mount /dev/shm from host

docker-compose.yml

@@ -18,11 +18,6 @@ services:
     volumes:
       - /tmp/.X11-unix:/tmp/.X11-unix:ro
       - $XDG_RUNTIME_DIR/pulse:/run/user/1000/pulse
-      # /dev/shm must be RW, otherwise webcam (/dev/video0) won't work
-      # mplayer tv:// -tv driver=v4l2:width=640:height=480:device=/dev/video0
-      #   X11 error: BadAccess (attempt to access private resource denied)
-      #   X11 error: BadShmSeg (invalid shared segment parameter)
-      - /dev/shm:/dev/shm
       - data:/data
       - certs:/home/user/.pki/nssdb
       - $HOME/Downloads:/home/user/Downloads
@@ -46,3 +41,4 @@ services:
     # fixes the: grsec: denied resource overstep by requesting 28 for RLIMIT_NICE against limit 0 for /opt/google/chrome/chrome
     ulimits:
       nice: 28
+    shm_size: 4G