message: Call c_str for regex ctor to resolve local string compat issues.
diff: @@ -422,7 +422,7 @@ RegexRouteEntryImpl::RegexRouteEntryImpl(const VirtualHostImpl& vhost,
  const envoy::api::v2::Route& route,
  Runtime::Loader& loader)
  : RouteEntryImplBase(vhost, route, loader),
  - regex_(std::regex{route.match().regex(), std::regex::optimize}) {}
  + regex_(std::regex{route.match().regex().c_str(), std::regex::optimize}) {}
  void RegexRouteEntryImpl::finalizeRequestHeaders(Http::HeaderMap& headers) const {
  RouteEntryImplBase::finalizeRequestHeaders(headers);
  