mailmap: add entry for obsolete email address

Map old corporate email address @yandex-team.ru to stable private address.
Signed-off-by: NKonstantin Khlebnikov <koct9i@gmail.com>
Link: https://lore.kernel.org/r/159360469186.24918.10108157093572183535.stgit@zurgSigned-off-by: NJonathan Corbet <corbet@lwn.net>

.mailmap

@@ -153,6 +153,7 @@ Kamil Konieczny <k.konieczny@samsung.com> <k.konieczny@partner.samsung.com>
 Kay Sievers <kay.sievers@vrfy.org>
 Kenneth W Chen <kenneth.w.chen@intel.com>
 Konstantin Khlebnikov <koct9i@gmail.com> <k.khlebnikov@samsung.com>
+Konstantin Khlebnikov <koct9i@gmail.com> <khlebnikov@yandex-team.ru>
 Koushik <raghavendra.koushik@neterion.com>
 Krzysztof Kozlowski <krzk@kernel.org> <k.kozlowski@samsung.com>
 Krzysztof Kozlowski <krzk@kernel.org> <k.kozlowski.k@gmail.com>