Fix signing issue with sha256 cert on 4.6.1 (#2931)
Fix signing issue with sha256 cert on 4.6.1 (#2931)

* Fix should only apply to RSACryptoServiceProvider

Microsoft/msbuild,mono/msbuild,Microsoft/msbuild,AndyGerlicher/msbuild,mono/msbuild,Microsoft/msbuild,chipitsine/msbuild,sean-gilliam/msbuild,mono/msbuild,jeffkl/msbuild,rainersigwald/msbuild,rainersigwald/msbuild,AndyGerlicher/msbuild,jeffkl/msbuild,Microsoft/msbuild,jeffkl/msbuild,AndyGerlicher/msbuild,cdmihai/msbuild,rainersigwald/msbuild,jeffkl/msbuild,sean-gilliam/msbuild,AndyGerlicher/msbuild,chipitsine/msbuild,cdmihai/msbuild,cdmihai/msbuild,cdmihai/msbuild,mono/msbuild,chipitsine/msbuild,sean-gilliam/msbuild,sean-gilliam/msbuild,rainersigwald/msbuild,chipitsine/msbuild