Read/write integer config entries depending on their signedness

With GnuPG 2.3 the type of some entries changed from unsigned int to int.

GnuPG-bug-id: 5217
2 jobs for master in 14 minutes and 10 seconds (queued for 5 minutes and 45 seconds)
Status Name Job ID Coverage
  Build
passed build_clazy_clang_tidy #100476

00:09:32

passed linux kf5-qt5 qt5.15 #100475

00:04:38

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