[PATCH] send-email: avoid duplicate specification warnings

[Todd Zullinger <tmz@pobox.com>]

With perl-Getopt-Long >= 2.55, a warning is issued for options which are
specified more than once.  In addition to causing users to see warnings,
this results in test failures which compare the output.  An example,
from t9001-send-email.37:

  | +++ diff -u expect actual
  | --- expect      2023-11-14 10:38:23.854346488 +0000
  | +++ actual      2023-11-14 10:38:23.848346466 +0000
  | @@ -1,2 +1,7 @@
  | +Duplicate specification "no-chain-reply-to" for option "no-chain-reply-to"
  | +Duplicate specification "to-cover|to-cover!" for option "to-cover"
  | +Duplicate specification "cc-cover|cc-cover!" for option "cc-cover"
  | +Duplicate specification "no-thread" for option "no-thread"
  | +Duplicate specification "no-to-cover" for option "no-to-cover"
  |  fatal: longline.patch:35 is longer than 998 characters
  |  warning: no patches were sent
  | error: last command exited with $?=1
  | not ok 37 - reject long lines

Remove the duplicate option specs.

Signed-off-by: Todd Zullinger <tmz@pobox.com>
---

I've run this through the full test suite.  I also compared the output of
--help to ensure it only differs in the removal of the "Duplicate
specification" warnings.  I _think_ that's a good sign that no other changes
will result.  But I would be grateful to anyone who can confirm or reject that
theory.

 git-send-email.perl | 16 +++-------------
 1 file changed, 3 insertions(+), 13 deletions(-)

diff --git a/git-send-email.perl b/git-send-email.perl
index cacdbd6bb2..13d9c47fe5 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -491,7 +491,6 @@ sub config_regexp {
 		    "bcc=s" => \@getopt_bcc,
 		    "no-bcc" => \$no_bcc,
 		    "chain-reply-to!" => \$chain_reply_to,
-		    "no-chain-reply-to" => sub {$chain_reply_to = 0},
 		    "sendmail-cmd=s" => \$sendmail_cmd,
 		    "smtp-server=s" => \$smtp_server,
 		    "smtp-server-option=s" => \@smtp_server_options,
@@ -506,36 +505,27 @@ sub config_regexp {
 		    "smtp-auth=s" => \$smtp_auth,
 		    "no-smtp-auth" => sub {$smtp_auth = 'none'},
 		    "annotate!" => \$annotate,
-		    "no-annotate" => sub {$annotate = 0},
 		    "compose" => \$compose,
 		    "quiet" => \$quiet,
 		    "cc-cmd=s" => \$cc_cmd,
 		    "header-cmd=s" => \$header_cmd,
 		    "no-header-cmd" => \$no_header_cmd,
 		    "suppress-from!" => \$suppress_from,
-		    "no-suppress-from" => sub {$suppress_from = 0},
 		    "suppress-cc=s" => \@suppress_cc,
-		    "signed-off-cc|signed-off-by-cc!" => \$signed_off_by_cc,
-		    "no-signed-off-cc|no-signed-off-by-cc" => sub {$signed_off_by_cc = 0},
-		    "cc-cover|cc-cover!" => \$cover_cc,
-		    "no-cc-cover" => sub {$cover_cc = 0},
-		    "to-cover|to-cover!" => \$cover_to,
-		    "no-to-cover" => sub {$cover_to = 0},
+		    "signed-off-by-cc!" => \$signed_off_by_cc,
+		    "cc-cover!" => \$cover_cc,
+		    "to-cover!" => \$cover_to,
 		    "confirm=s" => \$confirm,
 		    "dry-run" => \$dry_run,
 		    "envelope-sender=s" => \$envelope_sender,
 		    "thread!" => \$thread,
-		    "no-thread" => sub {$thread = 0},
 		    "validate!" => \$validate,
-		    "no-validate" => sub {$validate = 0},
 		    "transfer-encoding=s" => \$target_xfer_encoding,
 		    "format-patch!" => \$format_patch,
-		    "no-format-patch" => sub {$format_patch = 0},
 		    "8bit-encoding=s" => \$auto_8bit_encoding,
 		    "compose-encoding=s" => \$compose_encoding,
 		    "force" => \$force,
 		    "xmailer!" => \$use_xmailer,
-		    "no-xmailer" => sub {$use_xmailer = 0},
 		    "batch-size=i" => \$batch_size,
 		    "relogin-delay=i" => \$relogin_delay,
 		    "git-completion-helper" => \$git_completion_helper,