service: Always restart

The service may fail in case it gets exception on DBus, e.g. when BMC is
super busy and it gets "org.freedesktop.DBus.Error.Timeout" exception.

Make this service always restart so that it could always come back.

Signed-off-by: Lei YU <yulei.sh@bytedance.com>
Change-Id: Ib906d0a3c9cf5e79109099893454b2a78b4e495f
diff --git a/phosphor-virtual-sensor.service.in b/phosphor-virtual-sensor.service.in
index c687e09..46996aa 100644
--- a/phosphor-virtual-sensor.service.in
+++ b/phosphor-virtual-sensor.service.in
@@ -4,6 +4,7 @@
 After=obmc-mapper.target
 
 [Service]
+Restart=always
 ExecStart=@bindir@/virtual-sensor
 Type=dbus
 BusName=xyz.openbmc_project.VirtualSensor