remove an environment variable that was breaking unencrypted grpc con…

…nections

This overrode and made the following line useless:

AppContext.SetSwitch("System.Net.Http.SocketsHttpHandler.Http2UnencryptedSupport", true);

The resulting error was:

Unhandled exception. Grpc.Core.RpcException: Status(StatusCode=Internal, Detail="Bad gRPC response. Response protocol downgraded to HTTP/1.1.")

Further details in:

#4
grpc/grpc-dotnet#654
dotnet/runtime#988

scripts/dotnet.env

@@ -26,7 +26,6 @@ DOTNET_DIR=$(readlink -f "$scriptdir/../tools/dotnet")
 
 export DOTNET_SKIP_FIRST_TIME_EXPERIENCE=1
 export DOTNET_CLI_TELEMETRY_OPTOUT=1
-export DOTNET_SYSTEM_NET_HTTP_USESOCKETSHTTPHANDLER=0
 export DOTNET_ROLL_FORWARD_ON_NO_CANDIDATE_FX=2
 export DOTNET_ROOT="$DOTNET_DIR"