Rename branch master to main

.gitlab-ci.yml

@@ -14,7 +14,7 @@ variables:
     echo $CI_REGISTRY_PASSWORD | docker login -u $CI_REGISTRY_USER
     --password-stdin $CI_REGISTRY
   - |
-    if [[ $CI_COMMIT_BRANCH == "master" ]]; then
+    if [[ $CI_COMMIT_BRANCH == "main" ]]; then
       export CI_APP_REPO=${CI_APP_REPO:-$CI_REGISTRY_IMAGE}
       export CI_APP_TAG=${CI_APP_TAG:-latest}
     else