pg_basebackup: Fix progress messages when writing to a file
pg_basebackup: Fix progress messages when writing to a file

The progress messages print out \r to keep overwriting the same line on
the screen.  But this does not yield useful results when writing the
output to a file.  So in that case, print out \n instead.

Author: Martín Marqués <54669547a225ff20cba8b75a4adca540eef25858@2ndquadrant.com>
Reviewed-by: Arthur Zakirov <d62ca06f44b3f1ceb1de5f4e12a578718e4efc19@postgrespro.ru>

lisakowen/gpdb,greenplum-db/gpdb,greenplum-db/gpdb,adam8157/gpdb,adam8157/gpdb,50wu/gpdb,50wu/gpdb,greenplum-db/gpdb,adam8157/gpdb,xinzweb/gpdb,greenplum-db/gpdb,lisakowen/gpdb,lisakowen/gpdb,greenplum-db/gpdb,50wu/gpdb,greenplum-db/gpdb,lisakowen/gpdb,50wu/gpdb,greenplum-db/gpdb,xinzweb/gpdb,xinzweb/gpdb,50wu/gpdb,xinzweb/gpdb,50wu/gpdb,adam8157/gpdb,lisakowen/gpdb,xinzweb/gpdb,lisakowen/gpdb,lisakowen/gpdb,50wu/gpdb,adam8157/gpdb,adam8157/gpdb,xinzweb/gpdb,50wu/gpdb,xinzweb/gpdb,lisakowen/gpdb,greenplum-db/gpdb,xinzweb/gpdb,adam8157/gpdb,adam8157/gpdb