upstream: tweak the Nd lines for a bit of consistency; ok markus

OpenBSD-Commit-ID: 876651bdde06bc1e72dd4bd7ad599f42a6ce5a16
diff --git a/ssh-keygen.1 b/ssh-keygen.1
index 837238e..1b77bdf 100644
--- a/ssh-keygen.1
+++ b/ssh-keygen.1
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: ssh-keygen.1,v 1.178 2019/11/25 00:55:58 djm Exp $
+.\"	$OpenBSD: ssh-keygen.1,v 1.179 2019/11/30 07:07:59 jmc Exp $
 .\"
 .\" Author: Tatu Ylonen <ylo@cs.hut.fi>
 .\" Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -35,12 +35,12 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: November 25 2019 $
+.Dd $Mdocdate: November 30 2019 $
 .Dt SSH-KEYGEN 1
 .Os
 .Sh NAME
 .Nm ssh-keygen
-.Nd authentication key generation, management and conversion
+.Nd OpenSSH authentication key utility
 .Sh SYNOPSIS
 .Nm ssh-keygen
 .Op Fl q