Require GpgME 1.15.0
Increase the required version of GpgME and its C++ and Qt bindings to 1.15.0.
@bcooksley The CI already seems to use 1.16.0.
Increase the required version of GpgME and its C++ and Qt bindings to 1.15.0.
@bcooksley The CI already seems to use 1.16.0.