ipa-server-install: fix ca setup when fs.protected_regular=1
/tmp is a sticky directory. When the OS is configured with
fs.protected_regular=1, this means that O_CREATE open is forbidden
for files in /tmp if the calling user is not owner of the file,
except if the file is owned by the owner of the directory.
The installer (executed as root) currently creates a file in /tmp,
then modifies its owner to pkiuser and finally writes the pki config
in the file. With fs.protected_regular=1, the write is denied because
root is not owner of the file at this point.
The fix performs the ownership change after the file has been written.
Fedora bug: https://bugzilla.redhat.com/show_bug.cgi?id=1677027
Fixes: https://pagure.io/freeipa/issue/7866
Signed-off-by: François Cami <fcami@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>