Remove unused field.
Remove unused field.

Commit fb93e7e73f removed this field, but commit 9a817d4535 accidentally
resurrected it. Remove it again.

xinzweb/gpdb,50wu/gpdb,greenplum-db/gpdb,50wu/gpdb,kaknikhil/gpdb,edespino/gpdb,Chibin/gpdb,rvs/gpdb,ashwinstar/gpdb,xinzweb/gpdb,greenplum-db/gpdb,Quikling/gpdb,ashwinstar/gpdb,50wu/gpdb,janebeckman/gpdb,ashwinstar/gpdb,ashwinstar/gpdb,greenplum-db/gpdb,xinzweb/gpdb,edespino/gpdb,janebeckman/gpdb,xinzweb/gpdb,Quikling/gpdb,Chibin/gpdb,edespino/gpdb,adam8157/gpdb,Quikling/gpdb,Quikling/gpdb,janebeckman/gpdb,jmcatamney/gpdb,adam8157/gpdb,janebeckman/gpdb,kaknikhil/gpdb,xinzweb/gpdb,adam8157/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,cjcjameson/gpdb,rvs/gpdb,xinzweb/gpdb,Quikling/gpdb,cjcjameson/gpdb,edespino/gpdb,Quikling/gpdb,yuanzhao/gpdb,kaknikhil/gpdb,kaknikhil/gpdb,rvs/gpdb,Chibin/gpdb,cjcjameson/gpdb,cjcjameson/gpdb,ashwinstar/gpdb,yuanzhao/gpdb,greenplum-db/gpdb,Chibin/gpdb,kaknikhil/gpdb,janebeckman/gpdb,yuanzhao/gpdb,Chibin/gpdb,yuanzhao/gpdb,rvs/gpdb,lisakowen/gpdb,kaknikhil/gpdb,edespino/gpdb,Quikling/gpdb,kaknikhil/gpdb,edespino/gpdb,yuanzhao/gpdb,kaknikhil/gpdb,greenplum-db/gpdb,cjcjameson/gpdb,yuanzhao/gpdb,jmcatamney/gpdb,Quikling/gpdb,jmcatamney/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,Quikling/gpdb,cjcjameson/gpdb,Quikling/gpdb,Chibin/gpdb,50wu/gpdb,rvs/gpdb,rvs/gpdb,janebeckman/gpdb,yuanzhao/gpdb,50wu/gpdb,xinzweb/gpdb,adam8157/gpdb,edespino/gpdb,lisakowen/gpdb,cjcjameson/gpdb,jmcatamney/gpdb,janebeckman/gpdb,ashwinstar/gpdb,adam8157/gpdb,rvs/gpdb,lisakowen/gpdb,adam8157/gpdb,rvs/gpdb,cjcjameson/gpdb,greenplum-db/gpdb,lisakowen/gpdb,Chibin/gpdb,50wu/gpdb,janebeckman/gpdb,cjcjameson/gpdb,edespino/gpdb,jmcatamney/gpdb,Chibin/gpdb,cjcjameson/gpdb,lisakowen/gpdb,rvs/gpdb,ashwinstar/gpdb,edespino/gpdb,50wu/gpdb,yuanzhao/gpdb,yuanzhao/gpdb,kaknikhil/gpdb,janebeckman/gpdb,lisakowen/gpdb,lisakowen/gpdb,lisakowen/gpdb,xinzweb/gpdb,kaknikhil/gpdb,jmcatamney/gpdb,janebeckman/gpdb,Chibin/gpdb,jmcatamney/gpdb,50wu/gpdb,Chibin/gpdb,edespino/gpdb,adam8157/gpdb,rvs/gpdb,yuanzhao/gpdb,adam8157/gpdb