more bug fixing in release workflow

.github/workflows/release.yml

@@ -523,8 +523,8 @@ jobs:
         run: |
           for FILE in `find . -name "*.AppImage" -o -name "*.dmg" -o -name "*.msi" -o -name "*.zsync" -o -name "*.tar.gz"`; do
             CHECKSUM_MSG=$(sha256sum ${FILE})
-            VALUE=$(echo ${CHECKSUM} | sed 's/\([0-9,a-f]\{64\}\)[[:blank:]]\([Cc]ryptomator-.*$\)/\2: `\1`/' )
-            KEY=$(echo ${CHECKSUM} | sed 's/.*[[:blank:]].*\.\(.*$\)/\1/')
+            VALUE=$(echo ${CHECKSUM_MSG} | sed 's/\([0-9,a-f]\{64\}\)[[:blank:]]\([Cc]ryptomator-.*$\)/\2: `\1`/' )
+            KEY=$(echo ${CHECKSUM_MSG} | sed 's/.*[[:blank:]].*\.\(.*$\)/\1/')
             echo "{${KEY^^}_SHA256_MSG}={${VALUE}} >> $GITHUB_ENV
           done
       - name: Create release draft