fix: SubApp Issue #68 (KillMode=none)

templates/etc/systemd/user/subapp.service.j2

@@ -13,8 +13,10 @@ User={{ vault_subapp_user }}
 Group={{ vault_subapp_group }}
 # EXAMPLE: TimeoutSec=600
 TimeoutSec=infinity
-# PIDFile=subapp_bagit.pid
 PIDFile=/run/subapp/subapp_bagit.pid
+# DO NOT REMOVE!!! (based on SubApp Issue #68)
+# Do not kill any processes for a save shutdowns with a valid SubApp database.
+KillMode=none
 
 ### Security features
 # documented at https://www.freedesktop.org/software/systemd/man/systemd.exec.html