upstream: repair typo and editing mishap

OpenBSD-Commit-ID: d125ab720ca71ccf9baf83e08ddc8c12a328597e
diff --git a/sshsig.c b/sshsig.c
index 3dbdc85..ab9fe43 100644
--- a/sshsig.c
+++ b/sshsig.c
@@ -134,7 +134,7 @@
 	}
 
 	if ((r = sshbuf_b64tod(buf, b64)) != 0) {
-		error("Coundn't decode signature: %s", ssh_err(r));
+		error("Couldn't decode signature: %s", ssh_err(r));
 		goto done;
 	}