psql: Fix incorrect version check for table partitining.

Table partitioning was added in 10, not 9.6.

Fabrízio de Royes Mello, per report from Jeff Janes

src/bin/psql/describe.c

@@ -1808,7 +1808,7 @@ describeOneTableDetails(const char *schemaname,
 	}
 
 	/* Make footers */
-	if (pset.sversion >= 90600)
+	if (pset.sversion >= 100000)
 	{
 		/* Get the partition information  */
 		PGresult   *result;