This fixes the following issue where spice-vdagent would fail to start if the
spice-vdagent-sock socket file already existed:
spice-vdagentd: Fatal could not create the server socket
/run/spice-vdagentd/spice-vdagent-sock: Error binding to address: Address
already in use
The requirement is also modified to depend on dbus-system, a cue taken from
upstream's own systemd service file (see 'data/spice-vdagentd.service' in the
sources).
* gnu/services/spice.scm (spice-vdagent-activation): Delete procedure.
(spice-vdagent-shepherd-service): Fix indentation.
[requirement]: Replace udev by dbus-system.
[start]: Ensure the spice-vdagentd run-time directory exists and that the
spice-vdagent-sock socket file does *not* exist before forking the daemon.
* gnu/services/spice.scm (spice-vdagent-activation): Update runtime directory
from /var/run/spice-vdagentd to /run/spice-vdagentd.
(spice-vdagent-service-type): Specify a default value and fix indentation.
Passing 'make-forkexec-constructor' a string or several string arguments
has been deprecated since dmd 0.1.
* gnu/services/base.scm (rngd-service-type): In 'start' method, pass a
list as the first argument to 'make-forkexec-constructor'.
* gnu/services/desktop.scm (bluetooth-shepherd-service): Likewise.
* gnu/services/spice.scm (spice-vdagent-shepherd-service): Likewise.
