Fix webapp checkout part 2 (#14910)

* Fix webapp checkout part 2

* Use trap instead to not trigger fail commands before.

* Rm trap afterwards.

.circleci/config.yml

@@ -28,13 +28,10 @@ jobs:
           export WEBAPP_GIT_COMMIT=$(git rev-parse HEAD)
           echo "$WEBAPP_GIT_COMMIT"
 
+          trap 'npm ci && make build' ERR
           curl -f -o ./dist.tar.gz https://pr-builds.mattermost.com/mattermost-webapp/commit/${WEBAPP_GIT_COMMIT}/mattermost-webapp.tar.gz
-          if [[ $? == 0 ]]
-          then
-            mkdir ./dist && tar -xvf ./dist.tar.gz -C ./dist --strip-components=1
-          else
-            npm ci && make build
-          fi
+          mkdir ./dist && tar -xvf ./dist.tar.gz -C ./dist --strip-components=1
+          trap - ERR
       - persist_to_workspace:
           root: ~/mattermost
           paths: