b4 is having trouble with unicode emails

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

Hi Konstantin,

It looks like b4 does not like non-acsii in emails, and fails for emails
like "Marek Behún <kabel@kernel.org>":

dtor@dtor-ws:~/kernel/linux-next (get_gpiod_from_child-remove)$ b4 send --no-sign --not-me-too --to='Marek Behún <kabel@kernel.org>' -o patches/gpiod-from-child
Converted the branch to 4 messages
Populating To/Cc addresses
Will write out messages into patches/gpiod-from-child
Traceback (most recent call last):
  File "/usr/local/google/home/dtor/b4/b4/command.py", line 358, in <module>
    cmd()
  File "/usr/local/google/home/dtor/b4/b4/command.py", line 341, in cmd
    cmdargs.func(cmdargs)
  File "/usr/local/google/home/dtor/b4/b4/command.py", line 86, in cmd_send
    b4.ez.cmd_send(cmdargs)
  File "/usr/local/google/home/dtor/b4/b4/ez.py", line 1268, in cmd_send
    msg.add_header('To', b4.format_addrs(allto))
  File "/usr/local/google/home/dtor/b4/b4/__init__.py", line 2878, in format_addrs
    addrs.add(email.utils.formataddr(pair))  # noqa
  File "/usr/lib/python3.10/email/utils.py", line 91, in formataddr
    address.encode('ascii')
UnicodeEncodeError: 'ascii' codec can't encode character '\xfa' in position 9: ordinal not in range(128)
dtor@dtor-ws:~/kernel/linux-next (get_gpiod_from_child-remove)$ b4 send --no-sign --not-me-too --to='Marek Behun <kabel@kernel.org>' -o patches/gpiod-from-child
Converted the branch to 4 messages
Populating To/Cc addresses
Will write out messages into patches/gpiod-from-child
  0000-get-rid-of-devm_fwnode_get_-index_-gpiod_from_child.eml
  0001-devm_fwnode_get_gpiod_from_child-is-going-away-as-the-name-is-too-unwieldy-let-s-switch-to-using-the-new-devm_fwnode_gpiod_get.eml
  0002-devm_fwnode_get_gpiod_from_child-is-going-away-as-the-name-is-too-unwieldy-let-s-switch-to-using-the-new-devm_fwnode_gpiod_get.eml
  0003-now-that-there-are-no-more-users-of-these-apis-in-the-kernel-we-can-remove-them.eml
---
DRYRUN: Would have sent 4 messages

Thanks!

-- 
Dmitry