fix: no docker hub push merge requests

.gitlab-ci.yml

@@ -103,6 +103,7 @@ version:
         VERSION="unstable-mr-${CI_MERGE_REQUEST_PROJECT_ID}-${CI_MERGE_REQUEST_IID}"
         NIGHTLY_TAG="${VERSION}-nightly"
         EXPORT_TAG="${VERSION}"
+        DH_PUSH=""
       elif [[ "$CI_COMMIT_TAG" =~ ^v[0-9.]+\.[0-9]+\.[0-9]+ ]]; then
         VERSION="${CI_COMMIT_TAG:1}"
         EXPORT_TAG="${VERSION}"