Diffusion GPGME 3b782443600e

cpp: Fix use after free in gencardkeyinteractor

Authored by aheinecke on Aug 8 2018, 9:22 AM.

Description

cpp: Fix use after free in gencardkeyinteractor

* lang/cpp/src/gpggencardkeyinteractor.cpp
(GpgGenCardKeyInteractor::Private::keysize): Change to string.

The value is only required as string so we can save it this
way to avoid the need to convert it for the action command.