ObjCProtocol tries to create a ObjCPropertyDecl

Here is the line that is a problem. https://github.com/microsoft/ClangSharp/blob/6dd2e4e8e0a1018170c1c00cf76857c56b42649e/sources/ClangSharp/Cursors/Decls/Decl.cs#L170

The correct line is 
```csharp
CX_DeclKind.CX_DeclKind_ObjCProtocol => new ObjCProtocolDecl(handle),
```