Fix TSan report around condvar in host resolver (#3013)

* Fix TSan report around condvar in host resolver

* Update GeneralHTTPCredentialsProvider.cpp

Author: alexey-milovidov

src/aws-cpp-sdk-core/source/auth/GeneralHTTPCredentialsProvider.cpp

@@ -120,8 +120,13 @@ bool GeneralHTTPCredentialsProvider::ShouldCreateGeneralHTTPProvider(const Aws::
                 std::unique_lock<std::mutex> lock(hostResolverMutex);
                 shouldAllow = !addresses.empty();
                 hostResolved = true;
+                hostResolverCV.notify_one();
+              }
+              else
+              {
+                std::unique_lock<std::mutex> lock(hostResolverMutex);
+                hostResolverCV.notify_one();
               }
-              hostResolverCV.notify_one();
             };
           pHostResolver->ResolveHost(authority.c_str(), onHostResolved);
           std::unique_lock<std::mutex> lock(hostResolverMutex);