Fixes #241 - Fix build workflow (#249)

Author: mnriem

.github/workflows/build.yml

@@ -5,7 +5,7 @@ on:
       - 'current'
   pull_request:
     branches:
-      - '*'  
+      - '*'
   workflow_dispatch:
 jobs:
   build:
@@ -20,12 +20,14 @@ jobs:
     - name: Build with Maven
       run: mvn -B --ntp package
     - name: Login to GHCR
+      if: github.ref == 'refs/heads/current'
       uses: docker/login-action@v2
       with:
         registry: ghcr.io
-        username: ${{ secrets.GHCR_USERNAME }}
-        password: ${{ secrets.GHCR_TOKEN }}
+        username: ${{ secrets.GHCR_IO_USERNAME }}
+        password: ${{ secrets.GHCR_IO_PASSWORD }}
     - name: Push to GHCR
+      if: github.ref == 'refs/heads/current'
       run: |
         cd repo
         mvn --ntp -P docker install docker:build docker:push