doc: update mgol in AUTHORS.txt, add to .mailmap

PR-URL: #17239
Reviewed-By: Alexey Orlenko <eaglexrlnk@gmail.com>
Reviewed-By: Myles Borins <myles.borins@gmail.com>

Author: mgol

.mailmap

@@ -218,6 +218,7 @@ Michael Dawson <michael_dawson@ca.ibm.com> <mdawson@devrus.com>
 Michael Wilber <gcr@sneakygcr.net>
 Michaël Zasso <targos@protonmail.com> <mic.besace@gmail.com>
 Michael-Rainabba Richardson <rainabba@gmail.com> rainabba <rainabba@gmail.com>
+Michał Gołębiowski-Owczarek <m.goleb@gmail.com>
 Micheil Smith <micheil@brandedcode.com> <micheil@yettobebranded.net>
 Micleusanu Nicu <micnic90@gmail.com>
 Miguel Angel Asencio Hurtado <maasencioh@gmail.com> maasencioh <maasencioh@gmail.com>

AUTHORS

@@ -791,7 +791,7 @@ Salman Aljammaz <s@0x65.net>
 Thomas Reggi <thomas@reggi.com>
 Laurent Fortin <laurent.fortin@gmail.com>
 Fabio Oliveira <fabio.an.oliveira@gmail.com>
-Michał Gołębiowski <m.goleb@gmail.com>
+Michał Gołębiowski-Owczarek <m.goleb@gmail.com>
 Johann Hofmann <git@johann-hofmann.com>
 Charles Rudolph <charles.rudolph@originate.com>
 Dave Eddy <dave@daveeddy.com>