send-email: Cleanup { style

send-email: Cleanup { style

As Jakub Narebski pointed out on the list, Perl code usually prefers

  sub func {
  }

over

  sub func
  {
  }

git-send-email.perl is somewhat inconsistent in its style, with 23
subroutines using the first style and 6 using the second.  Convert the
few odd subroutines so that the code matches normal Perl style.

Signed-off-by: Brian Gernhardt <brian@gernhardtsoftware.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>