qt: Fix filename handling in cryptoconfig
* src/qgpgmenewcryptoconfig.cpp (QGpgMENewCryptoConfigEntry::urlValue): Build url from local file. (QGpgMENewCryptoConfigEntry::setURLValue): Set native seperated path.
This fixes setting files through cryptoconfig on Windows.
- GnuPG-Bug-Id: T3939