Removed unnecessary assertion for pxf fragments (#3094)
Removed unnecessary assertion for pxf fragments (#3094)


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