Rollup merge of rust-lang#39348 - steveklabnik:cyryl-mailmap, r=alexcrichton

Fix cyryl's mailmap entry

Author: alexcrichton

.mailmap

@@ -53,6 +53,7 @@ Clark Gaebel <cg.wowus.cg@gmail.com> <cgaebel@mozilla.com>
 Clinton Ryan <clint.ryan3@gmail.com>
 Corey Farwell <coreyf+rust@rwell.org> Corey Farwell <coreyf@rwell.org>
 Corey Richardson <corey@octayn.net> Elaine "See More" Nemo <corey@octayn.net>
+Cyryl Płotnicki <cyplo@cyplo.net>
 Damien Schoof <damien.schoof@gmail.com>
 Daniel Ramos <dan@daramos.com>
 David Klein <david.klein@baesystemsdetica.com>