init: add --force to ExecReload (caddyserver#84)

This caddy commit[1] adds --force flag, which helps to reload tls
certificates from disk when the config does not change.

This patch add this flag to ExecReload so that we can get this benefit
when using systemctl reload.

[1]: caddyserver/caddy@2772ede

init/caddy.service

@@ -24,7 +24,7 @@ Type=notify
 User=caddy
 Group=caddy
 ExecStart=/usr/bin/caddy run --environ --config /etc/caddy/Caddyfile
-ExecReload=/usr/bin/caddy reload --config /etc/caddy/Caddyfile
+ExecReload=/usr/bin/caddy reload --config /etc/caddy/Caddyfile --force
 TimeoutStopSec=5s
 LimitNOFILE=1048576
 LimitNPROC=512