t9001: use older Getopt::Long boolean prefix '--no' rather than '--no-'

Since dbf5e1e, the '--no-validate' option is a Getopt::Long boolean
option. The '--no-' prefix (as in --no-validate) for boolean options
is not supported in Getopt::Long version 2.32 which was released with
Perl 5.8.0. This version only supports '--no' as in '--novalidate'.
More recent versions of Getopt::Long, such as version 2.34, support
either prefix. So use the older form in the tests.

Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

t/t9001-send-email.sh

@@ -109,7 +109,7 @@ test_expect_success 'allow long lines with --no-validate' '
 		--from="Example <nobody@example.com>" \
 		--to=nobody@example.com \
 		--smtp-server="$(pwd)/fake.sendmail" \
-		--no-validate \
+		--novalidate \
 		$patches longline.patch \
 		2>errors
 '