[BUG] git-send-email broken: Can't locate object method "starttls"

Hi,

There seems to be a bug in 'git send-email' caused by this commit:

    commit 0ead000c3aca13a10ae51a3c74c866981e0d33b8
    Author: Dennis Kaarsemaker [off-list ref]
    Date:   Fri Mar 24 22:37:32 2017 +0100

        send-email: Net::SMTP::SSL is obsolete, use only when necessary

When running git send-email I get the following error:

	Can't locate object method "starttls" via package "Net::SMTP" at /usr/lib/git-core/git-send-email line 1410.

The perl version is 5.18.2, and the Net::SMTP version is 2.31.

I suspect the following line of code which appears to assume that starttls() is
present in Net::SMTP >= 1.28:

	my $use_net_smtp_ssl = version->parse($Net::SMTP::VERSION) < version->parse("1.28");

... but in fact it appears to have been added by the following commit to perl,
which bumped the Net::SMTP version from 2.34 up to 3.01:

	https://perl5.git.perl.org/perl.git/commit/2e1731446cd265cddae2ea6c43a375168fdb6f56

Eric