doc: Update ALTER SEQUENCE documentation to match
doc: Update ALTER SEQUENCE documentation to match

Update documentation to match change in
0bc1207aeb3de951bf95a9e9899b1256216d65f5.

adam8157/gpdb,greenplum-db/gpdb,xinzweb/gpdb,xinzweb/gpdb,50wu/gpdb,greenplum-db/gpdb,50wu/gpdb,50wu/gpdb,adam8157/gpdb,adam8157/gpdb,greenplum-db/gpdb,xinzweb/gpdb,adam8157/gpdb,lisakowen/gpdb,50wu/gpdb,xinzweb/gpdb,lisakowen/gpdb,50wu/gpdb,xinzweb/gpdb,xinzweb/gpdb,greenplum-db/gpdb,lisakowen/gpdb,adam8157/gpdb,greenplum-db/gpdb,greenplum-db/gpdb,lisakowen/gpdb,adam8157/gpdb,xinzweb/gpdb,50wu/gpdb,50wu/gpdb,adam8157/gpdb,lisakowen/gpdb,greenplum-db/gpdb,lisakowen/gpdb,xinzweb/gpdb,lisakowen/gpdb,50wu/gpdb,adam8157/gpdb,lisakowen/gpdb,greenplum-db/gpdb