Revert previous temporary patch

Author: simonat2ndQuadrant

contrib/pg_upgrade/controldata.c

@@ -621,12 +621,12 @@ check_control_data(ControlData *oldctrl,
 			   "options.\n");
 	}
 
-//	/* We might eventually allow upgrades from checksum to no-checksum clusters. */
-//	if (oldctrl->data_checksums != newctrl->data_checksums)
-//	{
-//		pg_log(PG_FATAL,
-//			   "old and new pg_controldata checksums settings are invalid or do not match\n");
-//	}
+	/* We might eventually allow upgrades from checksum to no-checksum clusters. */
+	if (oldctrl->data_checksums != newctrl->data_checksums)
+	{
+		pg_log(PG_FATAL,
+			   "old and new pg_controldata checksums settings are invalid or do not match\n");
+	}
 }