Fix pkgcs11 vcpkg port installing both debug and release files unconditionally

[lcruz99]

When VCPKG_BUILD_TYPE is set (either to release or debug), windows build fails during the vcpkg install phase when building pkcs11-helper.

pkcs11-helper portfile unconditionally attempts to install both release and debug artifacts:

CMake Error at .../pkcs11-helper/portfile.cmake:30 (file):
  file INSTALL cannot find
  "C:/vcpkg/buildtrees/pkcs11-helper/x64-windows-ovpn-dbg/lib/pkcs11-helper.dll.lib"

The PR fixes this by wrapping the release and debug file(INSTALL) commands with VCPKG_BUILD_TYPE guards, consistent with the existing pattern in the pkgconfig section:

if(NOT DEFINED VCPKG_BUILD_TYPE OR VCPKG_BUILD_TYPE STREQUAL "release")
  file(INSTALL ...-rel/lib/pkcs11-helper.dll.lib ...)
  file(INSTALL ...-rel/lib/libpkcs11-helper-1.dll ...)
endif()
if(NOT DEFINED VCPKG_BUILD_TYPE OR VCPKG_BUILD_TYPE STREQUAL "debug")
  file(INSTALL ...-dbg/lib/pkcs11-helper.dll.lib ...)
  file(INSTALL ...-dbg/lib/libpkcs11-helper-1.dll ...)
endif()