chore(nginx): consistent use of _HOST suffix

.env.example

@@ -52,7 +52,7 @@ NGINX_MAX_BODY_SIZE=10G
 FUNKWHALE_API_HOST=api
 FUNKWHALE_API_PORT=5000
 
-FUNKWHALE_FRONT_IP=front
+FUNKWHALE_FRONT_HOST=front
 FUNKWHALE_FRONT_PORT=${VUE_PORT}
 
 # postgres

compose/etc/nginx/conf.dev

@@ -4,7 +4,7 @@ upstream funkwhale-api {
 }
 
 upstream funkwhale-front {
-    server ${FUNKWHALE_FRONT_IP}:${FUNKWHALE_FRONT_PORT};
+    server ${FUNKWHALE_FRONT_HOST}:${FUNKWHALE_FRONT_PORT};
 }
 
 # Required for websocket support.

templates/nginx.conf.j2

@@ -19,7 +19,7 @@ upstream funkwhale-api {
 {% if config.proxy_frontend %}
 
 upstream funkwhale-front {
-    server ${FUNKWHALE_FRONT_IP}:${FUNKWHALE_FRONT_PORT};
+    server ${FUNKWHALE_FRONT_HOST}:${FUNKWHALE_FRONT_PORT};
 }
 {% endif %}