docs: update my e-mail

Since anciens.enib.fr has been dead for two months now, without any
hope of recovery, update my e-mail to point to @free.fr instead.

Reported-by: "Bryan Hundven" <bryanhundven@gmail.com>
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

 python

 import sys

 sys.path.insert(0, '@@PREFIX@@/share/gcc-@@VERSION@@/python')

 from libstdcxx.v6.printers import register_libstdcxx_printers

 register_libstdcxx_printers (None)

 end