Crash in ProxyConfigServiceTor

[iefremov]

Follow-up to #12798 that still reproduces

https://brave.sp.backtrace.io/p/brave/explore?time=month&filters=(ver%3E%3D%2290.1.23%22%2C(callstack%2Ccontains%2Cnet%3A%3AProxyConfigServiceTor%3A%3ASetProxyAuthorization))&aggregations=((ver%2Cmax)%2C(callstack%2Chead))&

[ 00 ] <name omitted>
[ 01 ] net::ProxyConfigServiceTor::SetProxyAuthorization(net::ProxyConfigWithAnnotation const&, GURL const&, net::ProxyResolutionService*, net::ProxyInfo*)
[ 02 ] net::ConfiguredProxyResolutionService::TryToCompleteSynchronously(GURL const&, net::ProxyInfo*)
[ 03 ] net::ConfiguredProxyResolutionService::ResolveProxy(GURL const&, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > const&, net::NetworkIsolationKey const&, net::ProxyInfo*, base::OnceCallback<void (int)>, std::__1::unique_ptr<net::ProxyResolutionRequest, std::__1::default_delete<net::ProxyResolutionRequest> >*, net::NetLogWithSource const&)
[ 04 ] <name omitted>
[ 05 ] network::NetworkContext::LookUpProxyForURL(GURL const&, net::NetworkIsolationKey const&, mojo::PendingRemote<network::mojom::ProxyLookupClient>)

[iefremov]

cc @darkdh

[iefremov]

fixed in #37884