Delete namespace if it exists

Fixes: #1037

.gitlab-ci.yml

@@ -75,6 +75,7 @@ install-helmrelease:
     # Make sure TLS certificate secrets for different MRs do not clash
     - sed -i "s/files-cert/files-cert-nc$CI_MERGE_REQUEST_IID/" values-ci.yaml
     - sed -i "s/office-cert/office-cert-nc$CI_MERGE_REQUEST_IID/" values-ci.yaml
+    - kubectl get namespace "nc$CI_MERGE_REQUEST_IID" && kubectl delete namespace "nc$CI_MERGE_REQUEST_IID"
     - kubectl create namespace "nc$CI_MERGE_REQUEST_IID"
     - helm install -n nc$CI_MERGE_REQUEST_IID --wait "nc$CI_MERGE_REQUEST_IID" . -f values-ci.yaml
   environment: