gpg: Fallback to import with self-sigs-only on too large keyblocks.

gpg: Fallback to import with self-sigs-only on too large keyblocks.

* g10/import.c (import_one): Rename to ...
(import_one_real): this.  Do not print and update stats on keyring
write errors.
(import_one): New.  Add fallback code.
--

GnuPG-bug-id: 4591
Signed-off-by: Werner Koch <wk@gnupg.org>
(cherry picked from commit 3a403ab04eeb45f12b34f9d9c421dac93eaf2160)
(cherry picked from commit a1f2f38dfb2ba5ed66d3aef66fc3be9b67f9b800)

Gbp-Pq: Topic from-2.2.17
Gbp-Pq: Name gpg-Fallback-to-import-with-self-sigs-only-on-too-large-k.patch