Add some retries at boot for times when udm-boot kicks in when network is not yet up. (#468)

* After restart on failure if some services are not yet available at boot

* Some more tunables tested on UDM-Pro

Author: ElCoyote27

on-boot-script/dpkg-build-files/udm-boot.service

@@ -2,9 +2,12 @@
 Description=Run On Startup UDM
 Wants=network-online.target
 After=network-online.target
+StartLimitIntervalSec=500
+StartLimitBurst=5
 
 [Service]
-Type=oneshot
+Restart=on-failure
+RestartSec=5s
 ExecStart=/sbin/ssh-proxy 'mkdir -p /mnt/data/on_boot.d && find -L /mnt/data/on_boot.d -mindepth 1 -maxdepth 1 -type f -print0 | sort -z | xargs -0 -r -n 1 -- sh -c '\''if test -x "$0"; then echo "%n: running $0"; "$0"; else case "$0" in *.sh) echo "%n: sourcing $0"; . "$0";; *) echo "%n: ignoring $0";; esac; fi'\'
 RemainAfterExit=true