Bug#767337: jetty8: Unable to purge if authbind is not installed

[Emmanuel Bourg]

Package: jetty8
Severity: normal

An error occurs on purging jetty8 when authbind is not installed:

Removing jetty8 (8.1.16-3) ...
Purging configuration files for jetty8 (8.1.16-3) ...
/usr/sbin/deluser: The user `jetty' does not exist.
rmdir: failed to remove â/etc/jetty8/contextsâ: No such file or directory
rmdir: failed to remove â/etc/authbind/byuidâ: No such file or directory
rmdir: failed to remove â/etc/authbindâ: No such file or directory
dpkg: error processing package jetty8 (--purge):
 subprocess installed post-removal script returned error exit status 1
Errors were encountered while processing:
 jetty8
E: Sub-process /usr/bin/dpkg returned an error code (1)