Correct LOG ERRORS document
Correct LOG ERRORS document

Error table feature was removed, but `\h CREATE EXTERNAL TABLE` still
has the description. This commit corrects it.

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