fix env variabled for docker-runner

templates/services/droneci-compose.yml.j2

@@ -73,7 +73,8 @@ services:
     privileged: true
     {% endif %}
     environment:
-      - DRONE_RPC_SERVER=http://droneserver
+      - DRONE_RPC_PROTO=http
+      - DRONE_RPC_HOST=droneserver
       - DRONE_RPC_SECRET={{ droneci_secret }}
       - DRONE_RUNNER_CAPACITY={{ droneci_agent_capacity }}
       # TODO: temp static value, needs to be replaced by a custom fact