docker fixes

docker-compose.dev.yml

@@ -1,7 +1,7 @@
 version: "2"
 services:
   flaskfetfotos:
-    image: docker.triton2.fet.at/flask-fet-fotos:latest
+    image: docker.fet.at/flask-fet-fotos:latest
     environment:
      FLASK_DEBUG: 0
      FLASK_APP: main.py
@@ -33,13 +33,13 @@ services:
     volumes:
      - /srv/etherpad/APIKEY.txt:/opt/etherpad-lite/APIKEY.txt
   theia:
-    image: docker.triton2.fet.at/theia-fet2020:latest
+    image: docker.fet.at/theia-fet2020:latest
     volumes:
       - dev_data:/home/project
       -  /srv/etherpad/APIKEY.txt:/srv/etherpad/APIKEY.txt
       - theia_usr:/usr/local
     environment:
-      HOST_NAME: andis.triton2.fet.at
+      HOST_NAME: '${HOSTNAME}'
   nginx:
     image: docker.triton2.fet.at/nginxdev-fet2020:latest
     ports: