fix AWS S3 startup for production deployments

Pass S3_REGION and S3_PUBLIC_USE_SSL through compose, treat blank public
SSL as unset, and skip CreateBucket when IAM only allows access to an
existing bucket.

docker-compose.yml

@@ -23,7 +23,9 @@ services:
       S3_ENDPOINT: ${S3_ENDPOINT:-seaweedfs:8333}
       S3_PUBLIC_ENDPOINT: ${S3_PUBLIC_ENDPOINT:-localhost:8333}
       S3_BUCKET: ${S3_BUCKET:-officeconvert}
+      S3_REGION: ${S3_REGION:-}
       S3_USE_SSL: ${S3_USE_SSL:-false}
+      S3_PUBLIC_USE_SSL: ${S3_PUBLIC_USE_SSL:-}
       S3_ACCESS_KEY: ${S3_ACCESS_KEY:-minioadmin}
       S3_SECRET_KEY: ${S3_SECRET_KEY:-minioadmin}
       S3_SESSION_TTL_SECONDS: ${S3_SESSION_TTL_SECONDS:-3600}