[ci skip] fix flathub workflow

.github/workflows/flathub.yml

@@ -56,7 +56,7 @@ jobs:
       - name: Update build file
         run: |
           sed -i -e 's/VERSION: [0-9]\+\.[0-9]\+\.[0-9]\+.*/VERSION: ${{ needs.get-version.outputs.semVerStr }}/g' org.cryptomator.Cryptomator.yaml
-          sed -i -e 's/sha512: [0-9A-Za-z_-\+]\{128\} #CRYPTOMATOR/sha512: ${{ needs.tarball.outputs.sha512 }} #CRYPTOMATOR/g' org.cryptomator.Cryptomator.yaml
+          sed -i -e 's/sha512: [0-9A-Za-z_\+-]\{128\} #CRYPTOMATOR/sha512: ${{ needs.tarball.outputs.sha512 }} #CRYPTOMATOR/g' org.cryptomator.Cryptomator.yaml
           sed -i -e 's;url: https://github.com/cryptomator/cryptomator/archive/refs/tags/[^[:blank:]]\+;url: ${{ needs.tarball.outputs.url }};g' org.cryptomator.Cryptomator.yaml
       - name: Commit and push
         run: |