fix: set relay to Montreal-based infra

vars/main.yml.example

@@ -9,6 +9,7 @@ pds_image_tag: "0.4"
 pds_blob_upload_limit: 314572800
 pds_rate_limits_enabled: true
 pds_invite_required: true
+pds_crawlers: https://relay.fire.hose.cam  # relay/crawler endpoint
 
 # S3 blob storage (uncomment to use instead of disk)
 # pds_blobstore_type: s3