Fix DockerHub deploy action

[skip CI]

Author: pierky

.github/workflows/docker_publish.yml

@@ -15,15 +15,15 @@ jobs:
         uses: actions/checkout@v2
         # Add the following 'with' to run this using the
         # 'on: push' trigger
-        # with:
-        #   ref: v1.4.0-alpha1
+        with:
+          ref: v1.4.0
 
       - name: Get the release
         run: echo "::set-output name=CURRENT_RELEASE::$(python -c 'from pierky.arouteserver.version import __version__; print(__version__)')"
         id: get_the_release
 
       - name: Is it a stable?
-        run: echo "::set-output name=IS_STABLE_RELEASE::$(echo ${{ steps.get_the_release.outputs.CURRENT_RELEASE }} | egrep '^\d+\.\d+\.\d+$' &>/dev/null && echo "true" || echo "false")"
+        run: echo "::set-output name=IS_STABLE_RELEASE::$(python -c 'from pierky.arouteserver.version import __version__; import re; import sys; re.match(r"^\d+\.\d+\.\d+$", __version__); sys.stdout.write(str(bool(re.match(r"^\d+\.\d+\.\d+$", __version__))))')"
         id: is_stable_release
 
       - name: Show the arguments
@@ -43,7 +43,7 @@ jobs:
           tags: pierky/arouteserver:${{ steps.get_the_release.outputs.CURRENT_RELEASE }}
 
       - name: Push to Docker Hub (latest)
-        if: steps.is_stable_release.outputs.IS_STABLE_RELEASE == 'true'
+        if: steps.is_stable_release.outputs.IS_STABLE_RELEASE == 'True'
         uses: docker/build-push-action@v2
         with:
           push: true