fix: the status page shows whether the Router Manager runs.

debian-package/src/usr/lib/vpn-router/web

@@ -258,6 +258,9 @@ def collect(state):
     """The status document. state says which features the router has."""
     units = {'vpn-router-setup': unit_state('vpn-router-setup.service'), 'slapd': unit_state('slapd.service'),
              **postgresql_clusters()}
+    manager_version = package_version('vpn-router-manager')
+    if manager_version:
+        units['vpn-router-manager'] = unit_state('vpn-router-manager.service')
     if state.get('site_to_site') or state.get('p2s'):
         units['strongswan'] = unit_state('strongswan.service')
     if state.get('wireguard'):
@@ -268,7 +271,7 @@ def collect(state):
     status = {
         'status': 'ok' if all(value == 'active' for value in units.values()) else 'degraded',
         'version': package_version(),
-        'manager_version': package_version('vpn-router-manager'),
+        'manager_version': manager_version,
         'time': time.strftime('%Y-%m-%dT%H:%M:%S%z'),
         'units': units,
         'docker': docker_status(),