win-dshow: Set MSVC runtime on virtual camera targets directly

The MSVC_RUNTIME_LIBRARY property is not propagated to targets which
link against a target which has this property set. Thus the property
needs to be set on the actual virtualcam targets and not the interface
library.
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f