pg_upgrade: force timeline 1 in the new cluster

Previously, this prevented promoted standby servers from being upgraded
because of a missing WAL history file.  (Timeline 1 doesn't need a
history file, and we don't copy WAL files anyway.)

Report by Christian Echerer(?), Alexey Klyukin

Backpatch through 9.0

contrib/pg_upgrade/pg_upgrade.c

@@ -512,8 +512,8 @@ copy_clog_xlog_xid(void)
 
 	/* now reset the wal archives in the new cluster */
 	prep_status("Resetting WAL archives");
-	exec_prog(true, SYSTEMQUOTE "\"%s/pg_resetxlog\" -l %u,%u,%u \"%s\" >> \"%s\" 2>&1" SYSTEMQUOTE,
-			  new_cluster.bindir, old_cluster.controldata.chkpnt_tli,
+	exec_prog(true, SYSTEMQUOTE "\"%s/pg_resetxlog\" -l 1,%u,%u \"%s\" >> \"%s\" 2>&1" SYSTEMQUOTE,
+			  new_cluster.bindir,
 			old_cluster.controldata.logid, old_cluster.controldata.nxtlogseg,
 			  new_cluster.pgdata,
 #ifndef WIN32