BUG/MINOR: http-htx: Don't normalize emtpy path for OPTIONS requests

When the scheme-based normalization is performed, an empty path is
normalized to "/". But as stated in RFC9110#4.2.3, this must not be applied
on OPTIONS requests.

So let's fix the issue by adding a test on the method.

Thanks to @zhanhb for the bug report and the analysis.

This patch should fix the issue #3352. It must be backported as far as 3.0.

src/http_htx.c

@@ -1867,7 +1867,7 @@ int http_scheme_based_normalize(struct htx *htx)
 		normalize = 1;
 	}
 
-	if (!isttest(path)) {
+	if (!isttest(path) && sl->info.req.meth != HTTP_METH_OPTIONS) {
 		path = ist("/");
 		normalize = 1;
 	}