revert: restore the ability to revert across case only renames (issue4481) This regressed in 5e16fe6fdd32, in what looks like an unrelated change. It seems sufficient to pass 'ignoremissing=True', but the restored try/except has been there for six years since 41bb88cb913e, so this seems safer for now. Note that renaming directories in the filename doesn't appear to work- not sure if this would end up throwing a different type of error when that is fixed.