INF-184 - Support the reverse proxy mode

- Switch the reverse proxy mode by var

Change-Id: I03c159ab0863eb935ed1b20fe6ec62a924d59aef
diff --git a/tasks/Debian.yml b/tasks/Debian.yml
index a3bd3ff..64a2d58 100644
--- a/tasks/Debian.yml
+++ b/tasks/Debian.yml
@@ -8,6 +8,7 @@
   apt:
     name:
       - "openjdk-{{ keycloak_java_version }}-jdk"
+      - "python3-lxml"
     state: "present"
     update_cache: true