Fix for strings with extra newlines/carriage returns

The \n escaping is working fine, but for HTML output that still has
weird returns, Javascript will take that as a newline and throw an
"Unterminated string literal" error in the browser-side. Removing \R
after the \n have been escaped solves the issue.

Thank you to bureado <https://github.com/bureado>, who authored this
change and commit.