upstream: grammar; a -> an

ok schwarze@ sthen@ krw@

OpenBSD-Commit-ID: adef73df2ccb7eac0e16a521f4dce6b8a72696b7

sftp-server.8

@@ -1,4 +1,4 @@
-.\" $OpenBSD: sftp-server.8,v 1.32 2026/05/21 02:50:59 djm Exp $
+.\" $OpenBSD: sftp-server.8,v 1.33 2026/08/25 00:08:28 jsg Exp $
 .\"
 .\" Copyright (c) 2000 Markus Friedl.  All rights reserved.
 .\"
@@ -22,7 +22,7 @@
 .\" (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: May 21 2026 $
+.Dd $Mdocdate: August 25 2026 $
 .Dt SFTP-SERVER 8
 .Os
 .Sh NAME
@@ -113,7 +113,7 @@ This flag, along with the
 .Fl p
 flag, may be used to disable operations that are irrelevant or undesirable
 for the server.
-For example, a
+For example, an
 .Nm
 that accepts connections from untrusted clients may wish to disable the
 .Dq copy-data