qt: Write path values with Unix directory separators
* lang/qt/src/qgpgmenewcryptoconfig.cpp (QGpgMENewCryptoConfigEntry::setURLValue): Remove conversion to native directory separators.
Even on Windows Unix directory separators work with all API calls. And
some path values also allow "URLs" like tcp://1.2.3.4:10001 which must
use '/'.
- GnuPG-bug-id: T4518