Move pre-7.3 platforms to unsupported.
Move pre-7.3 platforms to unsupported.

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