Allow reusing types from assemblies for projects targeting .net framework when adding WCF service.

[voroninp]

I've upgraded the project to SDK-style to discover that WCF referencing is broken.
I cannot add WCF reference and reuse types from another project which was the case for old project format.

This is quite a surprising behavior of Upgrade Assistant because it didn't even warn me about the presence of old WCF service reference.