Hit this while exercising Location.normalize with route paths that end in
non-.html suffixes. The unescaped . in the strip regex inside
_stripIndexHtml matches any character, so e.g. /foo/indexXhtml and
/foo/index_html both collapse to /foo before the base-path strip and end
up resolving to the wrong route. Escape the dot so only the literal
/index.html suffix is stripped.