Fix database test in gpstart
Fix database test in gpstart

Commit f41552e removed the upgrade code from gpstart, but took
some of the code to test connections with it. Reinstate the url
test but with self.dburl instead since it's the only remaining
value to test here.

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