remove --api.insecure now that Host() rule is fixed

Was added to debug the v3 multi-host parse error. Dashboard remains
reachable behind basicauth at traefik.t4t-gateway.com.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

hostinger/system-stack.yaml

@@ -50,7 +50,6 @@ services:
       - --certificatesresolvers.le.acme.tlschallenge=true
       - --api=true
       - --api.dashboard=true
-      - --api.insecure=true
       - --metrics.prometheus=true
       - --accesslog=true
       - --log=true