Fix PR pipeline pulling issue
Fix PR pipeline pulling issue

docker image jtarchie/pr updated recently, which breaks our git
submodule pulling, fall back to the working tag.

Signed-off-by: Adam Lee <b42a6d93d796915222f6ffb2ffdd6137d93c1cdb@pivotal.io>
Signed-off-by: Yuan Zhao <9640a31789aee25cf713d8aa6fe964eb05bab72b@pivotal.io>

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