Do not install the path unit when the service unit is not installed
for systemd-ask-password-wall.
Fixes the following warning on the CI:
[FAILED] Failed to start Forward Password Requests to Wall Directory Watch.
See 'systemctl status systemd-ask-password-wall.path' for details.
...
systemd[1]: systemd-ask-password-wall.path: Refusing to start, unit systemd-ask-password-wall.service to trigger not loaded.
systemd[1]: Failed to start Forward Password Requests to Wall Directory Watch.
inst_multiple -o \
"$systemdsystemunitdir"/systemd-ask-password-console.path \
"$systemdsystemunitdir"/systemd-ask-password-console.service \
- "$systemdsystemunitdir"/multi-user.target.wants/systemd-ask-password-wall.path \
"$systemdsystemunitdir"/sysinit.target.wants/systemd-ask-password-console.path \
systemd-ask-password \
systemd-tty-ask-password-agent