Use github ref name only for release

.github/workflows/modoboa.yml

@@ -174,6 +174,8 @@ jobs:
           yarn build
           cd ..
       - name: Build packages
+        env:
+          IS_RELEASE: yes
         run: |
           sudo apt-get install librrd-dev rrdtool libssl-dev
           python -m pip install --upgrade pip build

modoboa/version.py

@@ -8,7 +8,8 @@ def local_scheme(version):
 def get_version():
     from setuptools_scm import get_version as default_version
     github_version = os.environ.get('GITHUB_REF_NAME', None)
-    if github_version is not None:
+    is_release = os.environ.get('IS_RELEASE', None)
+    if is_release is not None and github_version is not None:
         return github_version
     return default_version(local_scheme=local_scheme)