UI/updater: Explicitly set PSAPI_VERSION=2

If the user didn't set their minimum SDK level this would default to
PSAPI_VERSION=1 which requires psapi.lib (removed in 4614c057).

UI/win-update/updater/CMakeLists.txt

@@ -32,7 +32,7 @@ set(updater_SOURCES
 	updater.manifest
 	)
 
-add_definitions(-DNOMINMAX -DUNICODE -D_UNICODE)
+add_definitions(-DNOMINMAX -DUNICODE -D_UNICODE -DPSAPI_VERSION=2)
 if(MSVC)
 	add_compile_options($<IF:$<CONFIG:Debug>,/MTd,/MT>)
 endif()