avoid setting a default path and query

Personally, I think defaulting to `/` if no path with query is set would
be the expected behavior, but wasip2 contained tests explicitly testing
against that behavior, so I disagree and commit

Signed-off-by: Roman Volosatovs <rvolosatovs@riseup.net>

Author: rvolosatovs

crates/wasi-http/src/p3/host/handler.rs

@@ -96,8 +96,6 @@ where
         };
         if let Some(path_with_query) = path_with_query {
             uri = uri.path_and_query(path_with_query)
-        } else {
-            uri = uri.path_and_query("/")
         };
         let uri = match uri.build() {
             Ok(uri) => uri,