runtime: System.Data.SqlClient cannot be found

Hi

In a specific scenario, I cannot load System.Data.SqlClient using the 2.0.6 runtime. The 2.0.5 runtime works.

A small repro : https://github.com/johnkors/sqlclient.runtime.test

A build of both runtimes: https://travis-ci.org/johnkors/sqlclient.runtime.test/builds/354338277

In 2.0.5, I can use System.Data.SqlClient (ok, it fails to connect to a unknown db here - but using the dll works). In 2.0.6, I get the FileNotFoundException.

Unhandled Exception: System.IO.FileNotFoundException: Could not load file or assembly ‘System.Data.SqlClient, Version=4.2.0.2, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a’. The system cannot find the file specified.

(bumping the the dependency on System.Data.SqlClient to 4.4.3 makes it work with both runtimes.)