Fix CmakeLists.txt for VS 2019

[Selora]

Hey there,
I'm too lazy to make a pull request. In order to make this work with VS2019, the following should be added to CMakeLists.txt in ./RpcCore:

RpcView/RpcCore/CMakeLists.txt

Line 26 in 60569c6

if(${CMAKE_GENERATOR} MATCHES "Win64")

to:

if(${CMAKE_GENERATOR} MATCHES "Win64")
            AddRpcCore(${Dir})
elseif(${CMAKE_GENERATOR_PLATFORM} MATCHES "x64")
	    AddRpcCore(${Dir})

Edit:
The following line should be used when building the project:
cmake -G"Visual Studio 16 2019" -A x64 ../../

This is all because they introduced a new semantic in CMAKE for VS2019.

Cheers