This adds the option "unsafe-accounts-conf" under the section [general]
of aerc.conf. This allows an user to specify if the accounts.conf file
must be restrict to be read by the file owner (0600).
By default it is set to "false".
Signed-off-by: Victor Freire <victor@freire.dev.br>
Acked-by: Robin Jarry <robin@jarry.cc>