httpclient_adapter: use uri after filters when building req signature

If a filter changes the URI (e.g. to enforce a protocol or change the
hostname of the request) this is currently unable to be mocked as
webmock fetches the URI for the signature of the request before calling
the filters!

lib/webmock/http_lib_adapters/httpclient_adapter.rb

@@ -157,14 +157,14 @@ def build_webmock_response(httpclient_response, body = nil)
     end
 
     def build_request_signature(req, reuse_existing = false)
-      uri = WebMock::Util::URI.heuristic_parse(req.header.request_uri.to_s)
-      uri.query = WebMock::Util::QueryMapper.values_to_query(req.header.request_query, notation: WebMock::Config.instance.query_values_notation) if req.header.request_query
-      uri.port = req.header.request_uri.port
-
       @request_filter.each do |filter|
         filter.filter_request(req)
       end
 
+      uri = WebMock::Util::URI.heuristic_parse(req.header.request_uri.to_s)
+      uri.query = WebMock::Util::QueryMapper.values_to_query(req.header.request_query, notation: WebMock::Config.instance.query_values_notation) if req.header.request_query
+      uri.port = req.header.request_uri.port
+
       headers = req.header.all.inject({}) do |hdrs, header|
         hdrs[header[0]] ||= []
         hdrs[header[0]] << header[1]