[#174] Fix router filter query matching

Signed-off-by: Denis Kirillov <d.kirillov@yadro.com>

api/router_filter.go

@@ -111,6 +111,15 @@ func (hf *HandlerFilters) DefaultHandler(handler http.HandlerFunc) *HandlerFilte
 }
 
 func (hf *HandlerFilters) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if handler := hf.match(r); handler != nil {
+		handler.ServeHTTP(w, r)
+		return
+	}
+
+	hf.defaultHandler.ServeHTTP(w, r)
+}
+
+func (hf *HandlerFilters) match(r *http.Request) http.Handler {
 LOOP:
 	for _, filter := range hf.filters {
 		for _, header := range filter.headers {
@@ -121,13 +130,12 @@ LOOP:
 		}
 		for _, query := range filter.queries {
 			queryVal := r.URL.Query().Get(query.Key)
-			if !r.URL.Query().Has(query.Key) || queryVal != "" && query.Value != queryVal {
+			if !r.URL.Query().Has(query.Key) || query.Value != "" && query.Value != queryVal {
 				continue LOOP
 			}
 		}
-		filter.h.ServeHTTP(w, r)
-		return
+		return filter.h
 	}
 
-	hf.defaultHandler.ServeHTTP(w, r)
+	return nil
 }