fix: [cron] ``dc`` command would fail in user environment

On user launched ``compose`` (using ``~/.compose/sessions`` as
session dir, the ``dc`` command would fail getting it's environment
file correctly, and subsequently would fail running.

Signed-off-by: Valentin Lab <valentin.lab@kalysto.org>

cron/hooks/init

@@ -19,6 +19,12 @@ fi
     exit 1
 }
 
+[ "$HOST_COMPOSE_LAUNCHER_OPTS" ] || {
+    err "\$HOST_COMPOSE_LAUNCHER_OPTS is expected to be set."
+    exit 1
+}
+
+
 [ "$COMPOSE_LAUNCHER_BIN" ] || {
     err "\$COMPOSE_LAUNCHER_BIN is expected to be set."
     exit 1
@@ -31,7 +37,7 @@ $CHARM_NAME:
     - /etc/timezone:/etc/timezone:ro
     - \$DOCKER_COMPOSE_PATH/bin/dc:/bin/dc:ro
     - $COMPOSE_LAUNCHER_BIN:/bin/compose:ro
-    - $COMPOSE_LAUNCHER_OPTS:$COMPOSE_LAUNCHER_OPTS:ro
+    - $HOST_COMPOSE_LAUNCHER_OPTS:$COMPOSE_LAUNCHER_OPTS:ro
   environment:
     TZ: $timezone
     COMPOSE_LAUNCHER_OPTS: $COMPOSE_LAUNCHER_OPTS