[satlab]: Fix compose upstart script for typo

Change-Id: I3c012edefad610e23e4b95ebc031c5e3edebafa8
Bug:b:224805980
Test: Manually tested on testbed
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/satlab/+/3527033
Reviewed-by: Anh Le <anhdle@chromium.org>
Commit-Queue: Prasad Vuppalapu <prasadv@chromium.org>
Auto-Submit: Prasad Vuppalapu <prasadv@chromium.org>
Reviewed-by: Prasad Vuppalapu <prasadv@chromium.org>
Tested-by: Prasad Vuppalapu <prasadv@chromium.org>
diff --git a/os-dependent/chromeos/upstart-scripts/satlab-compose-up.conf b/os-dependent/chromeos/upstart-scripts/satlab-compose-up.conf
index 4be18ad..f0e9818 100644
--- a/os-dependent/chromeos/upstart-scripts/satlab-compose-up.conf
+++ b/os-dependent/chromeos/upstart-scripts/satlab-compose-up.conf
@@ -88,7 +88,7 @@
     -v docker_config:/root/.docker \
     -v satlab_keys:/home/satlab/keys \
     -v cache_server:/home/satlab/cache_server \
-    -e DRONE_HOSTNAME=${DRONE_HOSTNAME}
+    -e DRONE_HOSTNAME=${DRONE_HOSTNAME} \
     -e LABEL=${LABEL} \
     -e SSH_PORT=${SSH_PORT} \
     --add-host dockerhost:172.17.0.1 \