Systemd executable path is not absolute

Describe the bug

Starting isc-stork-server.service generate an error on systemd in a Ubuntu 18.04.6.

# systemctl start isc-stork-server
Failed to start isc-stork-server.service: Unit isc-stork-server.service is not loaded properly: Exec format error.
See system logs and 'systemctl status isc-stork-server.service' for details.

# systemctl status isc-stork-server.service
● isc-stork-server.service - ISC Stork Server
   Loaded: error (Reason: Exec format error)
   Active: inactive (dead)
     Docs: man:stork-server(8)

fev 03 11:41:50 host systemd[1]: /lib/systemd/system/isc-stork-server.service:11: Executable path is not absolute: stork-server

To Reproduce

Steps to reproduce the behavior:

Install Stork 1.9.0.230131111251 ( by the book -> curl -1sLf 'https://dl.cloudsmith.io/public/isc/stork/cfg/setup/bash.deb.sh' | sudo bash )
apt install isc-stork-server
stork-tool db-create --db-name stork --db-user stork --db-host
stork-tool db-init --db-host --db-user stork --db-password
stork-tool db-up --db-host --db-user stork --db-password
Configure /etc/stork/server.env
systemctl enable isc-stork-server
systemctl start isc-stork-server

Expected behavior

Stork server start normally. Like this:

# systemctl status isc-stork-server
● isc-stork-server.service - ISC Stork Server
   Loaded: loaded (/lib/systemd/system/isc-stork-server.service; enabled; vendor preset: enabled)
   Active: active (running) since Fri 2023-02-03 11:44:45 -03; 18min ago
     Docs: man:stork-server(8)
 Main PID: 29201 (stork-server)
    Tasks: 9 (limit: 4915)
   CGroup: /system.slice/isc-stork-server.service
           └─29201 /usr/bin/stork-server

fev 03 12:01:45 host stork-server[29201]: time="2023-02-03 12:01:45" level="info" msg="Completed pulling hosts from Kea daemons" file="             host.go:111  " erred_count="0" skipped_count="0" success_count="0"
fev 03 12:01:45 host stork-server[29201]: time="2023-02-03 12:01:45" level="info" msg="Completed pulling DHCP status from Kea apps: 0/0 succeeded" file="           status.go:256  "
fev 03 12:01:45 host stork-server[29201]: time="2023-02-03 12:01:45" level="info" msg="Completed pulling information from machines: 0/0 succeeded" file="      statepuller.go:73   "
fev 03 12:02:15 host stork-server[29201]: time="2023-02-03 12:02:15" level="info" msg="Completed pulling information from machines: 0/0 succeeded" file="      statepuller.go:73   "
fev 03 12:02:15 host stork-server[29201]: time="2023-02-03 12:02:15" level="info" msg="Completed pulling DHCP status from Kea apps: 0/0 succeeded" file="           status.go:256  "
fev 03 12:02:45 host stork-server[29201]: time="2023-02-03 12:02:45" level="info" msg="Completed pulling stats from BIND 9 apps: 0/0 succeeded" file="      statspuller.go:62   "
fev 03 12:02:45 host stork-server[29201]: time="2023-02-03 12:02:45" level="info" msg="Completed pulling lease stats from Kea apps: 0/0 succeeded" file="      statspuller.go:71   "
fev 03 12:02:45 host stork-server[29201]: time="2023-02-03 12:02:45" level="info" msg="Completed pulling hosts from Kea daemons" file="             host.go:111  " erred_count="0" skipped_count="0" success_count="0"
fev 03 12:02:45 host stork-server[29201]: time="2023-02-03 12:02:45" level="info" msg="Completed pulling information from machines: 0/0 succeeded" file="      statepuller.go:73   "
fev 03 12:02:45 host stork-server[29201]: time="2023-02-03 12:02:45" level="info" msg="Completed pulling DHCP status from Kea apps: 0/0 succeeded" file="           status.go:256  "

Environment:

Stork: 1.9.0.230131111251
OS: Ubuntu 18.04.6 LTS - amd_64
systemd: 237-3ubuntu10.56

Additional Information

I'd tested another server, running Debian 11, and this error is not observed.

Stork version: 1.9.0.230131111251
OS: Debian GNU/Linux 11 (bullseye) - amd_64
systemd: 247.3-7+deb11u1

Describe the solution you'd like

Change the Unit ExecStart to :

ExecStart=/usr/bin/stork-server