* plugins.d/mandos-client.c (init_gpgme/import_key): If the system clock is not set, or set to january 1970, set the system clock to the more plausible value that is the mtime of the key file. This is required by GnuPG to be able to import the keys. (We can't pass the --ignore-time-conflict or the --ignore-valid-from options though GPGME.)