TrueNAS-Scale slash substitution.

- Changed a slash (/) to a dash (-) on the $cfg->{'pool'} reference.
SCST does not support '/' characters on the device.
- Possible fix for #75.

perl5/PVE/Storage/LunCmd/FreeNAS.pm

@@ -510,6 +510,8 @@ sub freenas_iscsi_create_extent {
 
     my $name = $lun_path;
     $name  =~ s/^.*\///; # all from last /
+    if ($product_name eq "TrueNAS-SCALE") {
+        $scfg->{'pool'} =~ s/\//-/;
     $name  = $scfg->{'pool'} . ($product_name eq "TrueNAS-SCALE" ? '-' : '/') . $name;
 
     my $device = $lun_path;