For GnuPG <2.2.28 add hint that GnuPG 2.2.28 is required
Options that are not supported by the currently used version of GnuPG
are still configurable to allow usage of Kleopatra with different
versions of GnuPG. Older versions of gpgsm will simply ignore the options.
- GnuPG-bug-id: T5465