barrel: Rename HOSTNAME=>WISSKI_HOSTNAME

This commit renames the HOSTNAME variable to WISSKI_HOSTNAME to avoid
breaking the container under specific circumstances.

internal/wisski/ingredient/barrel/barrel.env

@@ -2,7 +2,7 @@ DATA_PATH=${DATA_PATH}
 RUNTIME_DIR=${RUNTIME_DIR}
 
 SLUG=${SLUG}
-HOSTNAME=${HOSTNAME}
+WISSKI_HOSTNAME=${HOSTNAME}
 HOST_RULE=${HOST_RULE}
 DOCKER_NETWORK_NAME=${DOCKER_NETWORK_NAME}
 

internal/wisski/ingredient/barrel/barrel/docker-compose.yml

@@ -4,7 +4,7 @@ services:
   barrel:
     build: .
     restart: always
-    hostname: ${HOSTNAME}
+    hostname: ${WISSKI_HOSTNAME}
 
     # label it with the current slug
     labels: