component/xorg: don't share xserver

xserver tries to write in xkeyboard-config:

make[2]: Nothing to be done for 'install-exec-am'.
 /bin//mkdir -p '/tmp/slaps/shared/xkeyboard-config/02d353dc7c1ab898ea120142e33b42f6/share/X11/xkb/compiled'
/bin//mkdir: cannot create directory ‘/tmp/slaps/shared/xkeyboard-config/02d353dc7c1ab898ea120142e33b42f6/share/X11/xkb/compiled’: Permission denied
Makefile:730: recipe for target 'install-dist_xkbcompiledDATA' failed
make[2]: *** [install-dist_xkbcompiledDATA] Error 1

component/xorg/buildout.cfg

@@ -354,7 +354,6 @@ environment =
 
 [libxkbfile]
 recipe = slapos.recipe.cmmi
-shared = true
 url = https://www.x.org/releases/individual/lib/libxkbfile-1.0.9.tar.gz
 md5sum = 5aab87eba67f37dd910a19be5c1129ee
 environment =
@@ -365,7 +364,6 @@ environment =
 
 [xkeyboard-config]
 recipe = slapos.recipe.cmmi
-shared = true
 url = https://www.x.org/releases/individual/data/xkeyboard-config-2.5.1.tar.gz
 md5sum = 62c6583b4ec5775717e7c8b05732763c
 configure-options =
@@ -379,7 +377,6 @@ environment =
 
 [xkbcomp]
 recipe = slapos.recipe.cmmi
-shared = true
 url = https://www.x.org/releases/individual/app/xkbcomp-1.4.2.tar.gz
 md5sum = 84b6bafb660181a8c2572981a7fff54d
 # Hardcoded location for xkeyboard-config, needed during compile time
@@ -562,7 +559,6 @@ environment =
 
 [xwd]
 recipe = slapos.recipe.cmmi
-shared = true
 url = https://www.x.org/releases/individual/app/xwd-1.0.7.tar.gz
 md5sum = 3ebd74f7a1980305e5e19ec8ff7aa794
 environment =
@@ -574,7 +570,6 @@ environment =
 [xserver]
 # Adds Xvfb functionnality
 recipe = slapos.recipe.cmmi
-shared = true
 url = https://www.x.org/releases/individual/xserver/xorg-server-1.20.1.tar.gz
 md5sum = f5ba68452b1710306aabc32308c6ac59
 patches =