fix: missing url search when request auto redirect

[conwnet]

serve-handler will trim the ending .html suffix from url.pathname and make a redirect but forgot take the search, it may cause errors sometimes.

[pguilbert]

I have just encountered an issue related to this PR. All the query parameters are lost after the redirection:

For exemple: /test.html?var=123 is redirected to /test.

Can this be merged ?