Improve message about failed transaction log archiving
Improve message about failed transaction log archiving

The old phrasing appeared to imply that the failure was terminal.
Improve that by indicating that archiving will be tried again later.

adam8157/gpdb,50wu/gpdb,greenplum-db/gpdb,techdragon/Postgres-XL,greenplum-db/gpdb,lisakowen/gpdb,lisakowen/gpdb,50wu/gpdb,pavanvd/postgres-xl,jmcatamney/gpdb,adam8157/gpdb,ashwinstar/gpdb,zeroae/postgres-xl,oberstet/postgres-xl,zeroae/postgres-xl,ovr/postgres-xl,50wu/gpdb,lisakowen/gpdb,zeroae/postgres-xl,xinzweb/gpdb,jmcatamney/gpdb,pavanvd/postgres-xl,ovr/postgres-xl,oberstet/postgres-xl,adam8157/gpdb,jmcatamney/gpdb,adam8157/gpdb,ashwinstar/gpdb,yazun/postgres-xl,ashwinstar/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,ovr/postgres-xl,xinzweb/gpdb,adam8157/gpdb,techdragon/Postgres-XL,ashwinstar/gpdb,yazun/postgres-xl,pavanvd/postgres-xl,pavanvd/postgres-xl,xinzweb/gpdb,Postgres-XL/Postgres-XL,Postgres-XL/Postgres-XL,Postgres-XL/Postgres-XL,jmcatamney/gpdb,lisakowen/gpdb,zeroae/postgres-xl,greenplum-db/gpdb,ashwinstar/gpdb,jmcatamney/gpdb,techdragon/Postgres-XL,techdragon/Postgres-XL,lisakowen/gpdb,techdragon/Postgres-XL,lisakowen/gpdb,50wu/gpdb,greenplum-db/gpdb,ovr/postgres-xl,yazun/postgres-xl,xinzweb/gpdb,50wu/gpdb,lisakowen/gpdb,adam8157/gpdb,zeroae/postgres-xl,greenplum-db/gpdb,Postgres-XL/Postgres-XL,50wu/gpdb,jmcatamney/gpdb,jmcatamney/gpdb,xinzweb/gpdb,adam8157/gpdb,xinzweb/gpdb,pavanvd/postgres-xl,lisakowen/gpdb,jmcatamney/gpdb,50wu/gpdb,50wu/gpdb,xinzweb/gpdb,yazun/postgres-xl,oberstet/postgres-xl,Postgres-XL/Postgres-XL,xinzweb/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,ashwinstar/gpdb,oberstet/postgres-xl,ovr/postgres-xl,greenplum-db/gpdb,yazun/postgres-xl,adam8157/gpdb,oberstet/postgres-xl