CI: fix private key (#2001)

.github/workflows/deb.yml

@@ -60,9 +60,11 @@ jobs:
 
       - name: Setup Repository
         if: ${{ github.event_name == 'release' || github.event_name == 'workflow_dispatch' }}
+        env:
+          PRIVATE_KEY: ${{ secrets.DEBIAN_GPG_PRIVATE }}
         run: |
           git clone https://github.com/v2fly/debian.git archive
-          echo ${{ secrets.DEBIAN_GPG_PRIVATE }} | base64 -d > private.key
+          echo -n $PRIVATE_KEY | base64 -d > private.key
           gpg --import --batch private.key
           gpg -K
           cd archive