Revert "Win32: Roll back Gwenhywfar to 4.9.0 to resolve broken build."

This reverts commit 4e5e0621322147ff6ada9d72ace36e213dec61c7.
Preparing to revert its predecessor
Revert "Win32 build: Update aqbanking version numbers"

This reverts commit ae26a29fbd899272f4685b7d162932021ccb4ae7.
Gwen 4.10 and later breaks building GnuCash, and newer AQBanking
versions won't build with Gwen 4.9.