Fix assertion failure in single-user mode.
Fix assertion failure in single-user mode.

In single-user mode, MyQueueId isn't set. But there was an assertion for
that in ResourceQueueGetQueryMemoryLimit. To fix, don't apply memory limits
in single-user mode.

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