install: server-install: abort installation on permission issue
Abort installation if we do not have permissions to open the install
log for writing.
We use an environment variable to get the location to log the install
output to, since at the time the logging is initialized, the arguments
to ipsilon-server-install have not yet been parsed.
Signed-off-by: Patrick Uiterwijk <email@example.com>
Reviewed-by: Pierre-Yves Chibon <firstname.lastname@example.org>