NethServer 6

When no backup is configured, /usr/sbin/nethserver_dumper.pl script fails with an error:
Couldn't open location file: No such file or directory at /usr/sbin/nethserver_dumper.pl line 86.

Avoid the error skipping backup check if backup log file (/var/log/backup-data.log) doesn't exists.

Tested patch:

--- /usr/sbin/nethserver_dumper.pl.ori    2013-08-29 11:01:16.592113259 +0200
+++ /usr/sbin/nethserver_dumper.pl    2013-08-29 11:03:20.295931952 +0200
@@ -82,26 +82,31 @@

 # Backup
-my @lines;
-open (FILE, "/var/log/backup-data.log") or die "Couldn't open location file: $!";
-while (<FILE>) {
-    push(@lines, [split(' - ', $_)]);
-}
-close FILE;
-my @r = reverse(@lines);
-foreach my $field (0..@r-1) {
-   if ($r[$field][1] eq 'START') {
-       $dump_map{'BackupStart'} = str2time($r[$field][0]);
-       last;
-   }
-}
-$dump_map{'BackupEnd'} = str2time($lines[-1][0]);
-if ($lines[-1][1] eq "SUCCESS") {
-    $dump_map{'BackupResult'} = 0;
+if ( -f "/var/log/backup-data.log") {
+    my @lines;
+    open (FILE, "/var/log/backup-data.log") or die "Couldn't open location file: $!";
+    while (<FILE>) {
+        push(@lines, [split(' - ', $_)]);
+    }
+    close FILE;
+    my @r = reverse(@lines);
+    foreach my $field (0..@r-1) {
+       if ($r[$field][1] eq 'START') {
+           $dump_map{'BackupStart'} = str2time($r[$field][0]);
+           last;
+       }
+    }
+    $dump_map{'BackupEnd'} = str2time($lines[-1][0]);
+    if ($lines[-1][1] eq "SUCCESS") {
+        $dump_map{'BackupResult'} = 0;
+    } else {
+        $dump_map{'BackupResult'} = 1;
+    }
+    $dump_map{'BackupType'} = $db->get_prop('backup-data','VFSType') || "";
 } else {
-    $dump_map{'BackupResult'} = 1;
+    $dump_map{'BackupResult'} = 0;
+    $dump_map{'BackupType'} = "";
 }
-$dump_map{'BackupType'} = $db->get_prop('backup-data','VFSType') || "";

 # Raid
 sub broken_raid_devices {