import: drop '<' and '>' characters in addresses

import: drop '<' and '>' characters in addresses

Some strange "From:" lines will cause Email::Address::XS to
leave '<' (and presumably '>') in the address which
git-fast-import won't accept even if quoted.  Workaround this
problem by deleting '<' and '>' the same way we delete them for
the ident name.

Reported-by: Leah Neukirchen <leah@vuxu.org>
Link: https://public-inbox.org/meta/87h7zfemur.fsf@vuxu.org/