Fix ready sizeNew from last backup (except when link hasn't ran yet)

zabbix_scripts/check_backuppc_sudo

@@ -90,10 +90,10 @@ if ( $host ) {
     $json->{history_size}    = $json->{total_size} - $json->{full_size};
     $json->{age}             = time - $bpc_info[$i]->{startTime};
 
-    # For newSize, we need to wait for BackupPC_link to run, which can be delayed
+    # For sizeNew, we need to wait for BackupPC_link to run, which can be delayed
     # if a nightly process is running. In this case, use the stats from the previous backup
     # Except when we ave a single backup, in which case we read stats of this only backup
-    $i = ( $backup->{sizeNew} || scalar @bpc_info == 1 ) ? -1 : -2;
+    $i = ( $bpc_info[-1]->{sizeNew} || scalar @bpc_info == 1 ) ? -1 : -2;
     $json->{new_size}   = $bpc_info[$i]->{sizeNew};
     $json->{comp_ratio} = ( $bpc_info[$i]->{sizeNew} > 0 ) ?
         sprintf( "%.2f", 100 - ( $bpc_info[$i]->{sizeNewComp} * 100 / $bpc_info[$i]->{sizeNew} ) )