Fix force bucket deletion in distributed mode (#12659)

storageRESTForceDelete is not always passed by client, use r.URL().Query
instead.

Co-authored-by: Anis Elleuch <anis@min.io>

cmd/storage-rest-server.go

@@ -282,7 +282,7 @@ func (s *storageRESTServer) DeleteVolHandler(w http.ResponseWriter, r *http.Requ
 	}
 	vars := mux.Vars(r)
 	volume := vars[storageRESTVolume]
-	forceDelete := vars[storageRESTForceDelete] == "true"
+	forceDelete := r.URL.Query().Get(storageRESTForceDelete) == "true"
 	err := s.storage.DeleteVol(r.Context(), volume, forceDelete)
 	if err != nil {
 		s.writeErrorResponse(w, err)