mailmap: Fix Stefan Weil author email

Fix authorship of commits 266aaedc37~..ac14949821. See commit
3bd2608db7 ("maint: Add .mailmap entries for patches claiming
list authorship") for rationale.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20221208155535.28363-1-philmd@linaro.org>

.mailmap

@@ -45,6 +45,7 @@ Ed Swierk <eswierk@skyportsystems.com> Ed Swierk via Qemu-devel <qemu-devel@nong
 Ian McKellar <ianloic@google.com> Ian McKellar via Qemu-devel <qemu-devel@nongnu.org>
 Julia Suvorova <jusual@mail.ru> Julia Suvorova via Qemu-devel <qemu-devel@nongnu.org>
 Justin Terry (VM) <juterry@microsoft.com> Justin Terry (VM) via Qemu-devel <qemu-devel@nongnu.org>
+Stefan Weil <sw@weilnetz.de> Stefan Weil via <qemu-devel@nongnu.org>
 
 # Next, replace old addresses by a more recent one.
 Aleksandar Markovic <aleksandar.qemu.devel@gmail.com> <aleksandar.markovic@mips.com>