systemd: set restart=always for zfs-zed.service

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: George Melikov <mail@gmelikov.ru>
Co-authored-by: Attila Fülöp <attila@fueloep.org>
Closes #14294

etc/systemd/system/zfs-zed.service.in

@@ -6,7 +6,7 @@ ConditionPathIsDirectory=/sys/module/zfs
 [Service]
 EnvironmentFile=-@initconfdir@/zfs
 ExecStart=@sbindir@/zed -F
-Restart=on-abort
+Restart=always
 
 [Install]
 Alias=zed.service