fix: router setup hangs on race condition with Docker.

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

@@ -318,7 +318,9 @@ def refresh_docker_rules():
     """Apply the new settings to the Docker rules while Docker is running.
 
     When Docker is not running, vpn-router-docker applies them after
-    docker.service starts.
+    docker.service starts. The restart is waited for, so the rules are in place
+    when this setup ends; vpn-router-docker is therefore not ordered after
+    vpn-router-setup.
     """
     if unit_is_active('docker.service'):
         run(['systemctl', 'restart', 'vpn-router-docker.service'], check=False)
@@ -332,7 +334,8 @@ def refresh_web(cfg, ctx):
     secrets masked and the facts resolved from the system from a file here, so
     that it needs nothing but the standard library and the configuration code.
     The file is readable by root only. The service ends quietly when
-    web.enabled is false.
+    web.enabled is false. The restart is queued, not waited for, because the
+    unit is ordered after vpn-router-setup.
     """
     masked = {
         section: {option: '********' if SECRET_OPTION.search(option) and value else value
@@ -363,7 +366,7 @@ def refresh_web(cfg, ctx):
             'remote_cidrs': ctx['remote_cidr_list'],
         },
     }) + '\n', encoding='utf-8')
-    run(['systemctl', 'restart', 'vpn-router-web.service'], check=False)
+    run(['systemctl', 'restart', '--no-block', 'vpn-router-web.service'], check=False)
 
 
 def main():