Fix MS VC 2019 build:
Fix MS VC 2019 build:

C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Tools\MSVC\14.29.30133\include\xmemory(714): error C2280: 'std::pair<const libMesh::FEType,std::unique_ptr<libMesh::FEAbstract,std::default_delete<libMesh::FEAbstract>>>::pair(const std::pair<const libMesh::FEType,std::unique_ptr<libMesh::FEAbstract,std::default_delete<libMesh::FEAbstract>>> &)': attempting to reference a deleted function

jwpeterson/libmesh,jwpeterson/libmesh,dschwen/libmesh,dschwen/libmesh,libMesh/libmesh,libMesh/libmesh,dschwen/libmesh,jwpeterson/libmesh,BalticPinguin/libmesh,libMesh/libmesh,dschwen/libmesh,BalticPinguin/libmesh,dschwen/libmesh,libMesh/libmesh,jwpeterson/libmesh,BalticPinguin/libmesh,dschwen/libmesh,libMesh/libmesh,jwpeterson/libmesh,jwpeterson/libmesh,BalticPinguin/libmesh,libMesh/libmesh,jwpeterson/libmesh,BalticPinguin/libmesh,BalticPinguin/libmesh,BalticPinguin/libmesh,jwpeterson/libmesh,libMesh/libmesh,dschwen/libmesh,BalticPinguin/libmesh,dschwen/libmesh,libMesh/libmesh