Make sure we produce a useful error message for the case where the postgresql.crt file simply isn't there, too.
Make sure we produce a useful error message for the case where the
postgresql.crt file simply isn't there, too.

adam8157/gpdb,greenplum-db/gpdb,postmind-net/postgres-xl,oberstet/postgres-xl,jmcatamney/gpdb,jmcatamney/gpdb,cjcjameson/gpdb,Chibin/gpdb,ovr/postgres-xl,foyzur/gpdb,kmjungersen/PostgresXL,edespino/gpdb,techdragon/Postgres-XL,CraigHarris/gpdb,tpostgres-projects/tPostgres,Chibin/gpdb,xuegang/gpdb,pavanvd/postgres-xl,tpostgres-projects/tPostgres,foyzur/gpdb,Postgres-XL/Postgres-XL,greenplum-db/gpdb,kmjungersen/PostgresXL,ashwinstar/gpdb,chrishajas/gpdb,rvs/gpdb,jmcatamney/gpdb,xinzweb/gpdb,ashwinstar/gpdb,CraigHarris/gpdb,Chibin/gpdb,randomtask1155/gpdb,zaksoup/gpdb,tangp3/gpdb,postmind-net/postgres-xl,Quikling/gpdb,Chibin/gpdb,yazun/postgres-xl,Chibin/gpdb,rubikloud/gpdb,lisakowen/gpdb,lintzc/gpdb,xuegang/gpdb,lisakowen/gpdb,foyzur/gpdb,randomtask1155/gpdb,lisakowen/gpdb,atris/gpdb,yuanzhao/gpdb,xinzweb/gpdb,lintzc/gpdb,Quikling/gpdb,atris/gpdb,kaknikhil/gpdb,0x0FFF/gpdb,greenplum-db/gpdb,ovr/postgres-xl,xinzweb/gpdb,edespino/gpdb,atris/gpdb,edespino/gpdb,cjcjameson/gpdb,royc1/gpdb,cjcjameson/gpdb,jmcatamney/gpdb,foyzur/gpdb,cjcjameson/gpdb,adam8157/gpdb,zeroae/postgres-xl,tpostgres-projects/tPostgres,50wu/gpdb,pavanvd/postgres-xl,Chibin/gpdb,edespino/gpdb,50wu/gpdb,yuanzhao/gpdb,foyzur/gpdb,snaga/postgres-xl,chrishajas/gpdb,0x0FFF/gpdb,Quikling/gpdb,rvs/gpdb,xuegang/gpdb,adam8157/gpdb,lintzc/gpdb,randomtask1155/gpdb,tangp3/gpdb,chrishajas/gpdb,postmind-net/postgres-xl,xuegang/gpdb,jmcatamney/gpdb,Quikling/gpdb,Quikling/gpdb,rubikloud/gpdb,rubikloud/gpdb,Quikling/gpdb,kmjungersen/PostgresXL,xuegang/gpdb,kaknikhil/gpdb,ahachete/gpdb,royc1/gpdb,jmcatamney/gpdb,cjcjameson/gpdb,ahachete/gpdb,CraigHarris/gpdb,pavanvd/postgres-xl,royc1/gpdb,lpetrov-pivotal/gpdb,xinzweb/gpdb,ahachete/gpdb,chrishajas/gpdb,zaksoup/gpdb,CraigHarris/gpdb,royc1/gpdb,ashwinstar/gpdb,greenplum-db/gpdb,snaga/postgres-xl,techdragon/Postgres-XL,Chibin/gpdb,rvs/gpdb,randomtask1155/gpdb,janebeckman/gpdb,Quikling/gpdb,tangp3/gpdb,kaknikhil/gpdb,lintzc/gpdb,yuanzhao/gpdb,zaksoup/gpdb,lpetrov-pivotal/gpdb,zaksoup/gpdb,xuegang/gpdb,rvs/gpdb,lpetrov-pivotal/gpdb,cjcjameson/gpdb,xuegang/gpdb,zeroae/postgres-xl,janebeckman/gpdb,zeroae/postgres-xl,CraigHarris/gpdb,kaknikhil/gpdb,kaknikhil/gpdb,janebeckman/gpdb,CraigHarris/gpdb,atris/gpdb,lisakowen/gpdb,Postgres-XL/Postgres-XL,ovr/postgres-xl,janebeckman/gpdb,0x0FFF/gpdb,arcivanov/postgres-xl,atris/gpdb,Postgres-XL/Postgres-XL,tangp3/gpdb,foyzur/gpdb,yuanzhao/gpdb,0x0FFF/gpdb,janebeckman/gpdb,Chibin/gpdb,ahachete/gpdb,adam8157/gpdb,ahachete/gpdb,chrishajas/gpdb,snaga/postgres-xl,lintzc/gpdb,lpetrov-pivotal/gpdb,techdragon/Postgres-XL,janebeckman/gpdb,50wu/gpdb,Chibin/gpdb,rubikloud/gpdb,lpetrov-pivotal/gpdb,greenplum-db/gpdb,0x0FFF/gpdb,lpetrov-pivotal/gpdb,CraigHarris/gpdb,ovr/postgres-xl,rvs/gpdb,atris/gpdb,kaknikhil/gpdb,adam8157/gpdb,yuanzhao/gpdb,janebeckman/gpdb,techdragon/Postgres-XL,atris/gpdb,lintzc/gpdb,arcivanov/postgres-xl,Quikling/gpdb,50wu/gpdb,ovr/postgres-xl,lintzc/gpdb,adam8157/gpdb,cjcjameson/gpdb,yuanzhao/gpdb,lisakowen/gpdb,edespino/gpdb,50wu/gpdb,yuanzhao/gpdb,xinzweb/gpdb,yazun/postgres-xl,oberstet/postgres-xl,snaga/postgres-xl,rubikloud/gpdb,yuanzhao/gpdb,ahachete/gpdb,rvs/gpdb,lintzc/gpdb,tangp3/gpdb,0x0FFF/gpdb,pavanvd/postgres-xl,0x0FFF/gpdb,edespino/gpdb,atris/gpdb,adam8157/gpdb,arcivanov/postgres-xl,yazun/postgres-xl,arcivanov/postgres-xl,ahachete/gpdb,xuegang/gpdb,ashwinstar/gpdb,Quikling/gpdb,ashwinstar/gpdb,xinzweb/gpdb,rvs/gpdb,ashwinstar/gpdb,lisakowen/gpdb,randomtask1155/gpdb,kaknikhil/gpdb,ahachete/gpdb,yazun/postgres-xl,xinzweb/gpdb,yazun/postgres-xl,postmind-net/postgres-xl,kaknikhil/gpdb,techdragon/Postgres-XL,oberstet/postgres-xl,jmcatamney/gpdb,tangp3/gpdb,arcivanov/postgres-xl,royc1/gpdb,zaksoup/gpdb,zeroae/postgres-xl,rubikloud/gpdb,ashwinstar/gpdb,tpostgres-projects/tPostgres,greenplum-db/gpdb,adam8157/gpdb,royc1/gpdb,50wu/gpdb,xinzweb/gpdb,0x0FFF/gpdb,edespino/gpdb,greenplum-db/gpdb,zeroae/postgres-xl,rvs/gpdb,50wu/gpdb,CraigHarris/gpdb,50wu/gpdb,pavanvd/postgres-xl,randomtask1155/gpdb,postmind-net/postgres-xl,yuanzhao/gpdb,janebeckman/gpdb,foyzur/gpdb,kmjungersen/PostgresXL,chrishajas/gpdb,zaksoup/gpdb,Quikling/gpdb,royc1/gpdb,kmjungersen/PostgresXL,lisakowen/gpdb,tangp3/gpdb,tangp3/gpdb,zaksoup/gpdb,rvs/gpdb,lpetrov-pivotal/gpdb,Postgres-XL/Postgres-XL,zaksoup/gpdb,edespino/gpdb,royc1/gpdb,rvs/gpdb,cjcjameson/gpdb,chrishajas/gpdb,rubikloud/gpdb,ashwinstar/gpdb,lintzc/gpdb,edespino/gpdb,jmcatamney/gpdb,kaknikhil/gpdb,janebeckman/gpdb,xuegang/gpdb,janebeckman/gpdb,tpostgres-projects/tPostgres,cjcjameson/gpdb,lisakowen/gpdb,oberstet/postgres-xl,foyzur/gpdb,Chibin/gpdb,yuanzhao/gpdb,randomtask1155/gpdb,oberstet/postgres-xl,Postgres-XL/Postgres-XL,cjcjameson/gpdb,CraigHarris/gpdb,kaknikhil/gpdb,arcivanov/postgres-xl,lpetrov-pivotal/gpdb,snaga/postgres-xl,greenplum-db/gpdb,randomtask1155/gpdb,chrishajas/gpdb,rubikloud/gpdb,edespino/gpdb