Update the release tarball checksum
    
    Upstream has replaced the v1.4.0 tag, moving it from commit
    b42a3ad2ce265a2353325160e25b0e5d5083da11 to commit
    8268181c66379f7392c93ae62a1286bc42f333ee.  The actual code changes
    are contained in release.sh which is not used by this package, so
    there is no impact to the binary RPMs.