Remove LOAD_BYPASS_PROXY flag from hints fetcher request.

This is unneeded.

Bug: 1013380
Test: Built and fetched hints on device.
Change-Id: I9f7d3fbfc15d199e14d6c760dfe3d0fb41363ba2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1873344Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Commit-Queue: Josh Simmons <jds@google.com>
Cr-Commit-Position: refs/heads/master@{#708400}

components/optimization_guide/hints_fetcher.cc

@@ -161,7 +161,6 @@ bool HintsFetcher::FetchOptimizationGuideServiceHints(
   resource_request->url = optimization_guide_service_url_;
 
   resource_request->method = "POST";
-  resource_request->load_flags = net::LOAD_BYPASS_PROXY;
   resource_request->credentials_mode = network::mojom::CredentialsMode::kOmit;
 
   url_loader_ = network::SimpleURLLoader::Create(std::move(resource_request),