don't unconditionally strip last character from *.html/*.txt in %prep
    
    It's unclear what the original intent was in `sed -i 's/.$//'` run on
    the .html and .txt files in the source.  It's been there since the
    initial commit.
    
    It seems like the intent was to normalize the line endings.  Do this
    using `sed -i 's/.$//'` instead, to only replace CR/LF with LF.