Update maintainer list

[skip ci]

libs/maintainers.txt

@@ -99,6 +99,7 @@ msm                   Christophe Henry <christophe.j.henry -at-  googlemail.com>
 multi_array           Ronald Garcia <garcia -at- osl.iu.edu>
 multi_index           Joaquin M Lopez Munoz <joaquin.lopezmunoz -at- gmail.com>
 multiprecision        John Maddock <john -at- johnmaddock.co.uk>, christopher Kormanyos <e_float -at- yahoo.com>
+mysql                 Rubén Pérez <rubenperez038@gmail.com>
 nowide                Alexander Grund <alex -at- grundis.de>
 numeric/conversion    Fernando Cacciola <fernando_cacciola -at- ciudad.com.ar>, Brandon Kohn <blkohn -at- hotmail.com>
 numeric/interval      Sylvain Pion <Sylvain.Pion -at- sophia.inria.fr>, Herve Bronnimann <hbr -at- poly.edu>, Guillaume Melquiond <guillaume.melquiond -at- ens-lyon.fr>