mail: pass ui to sslutil.wrapsocket() even if verifycert is off (issue4713)

21b536f01eda made 'ui' argument is passed via sslutil.sslkwargs(), but mailer
doesn't call sslkwargs() if smtp.verifycert is off. So we have to put it in
sslkwargs manually.

mercurial/mail.py

@@ -104,7 +104,8 b' def _smtp(ui):'
     if (starttls or smtps) and verifycert:
         sslkwargs = sslutil.sslkwargs(ui, mailhost)
     else:
-        sslkwargs = {}
+        # 'ui' is required by sslutil.wrapsocket() and set by sslkwargs()
+        sslkwargs = {'ui': ui}
     if smtps:
         ui.note(_('(using smtps)\n'))
         s = SMTPS(sslkwargs, local_hostname=local_hostname)