followup comment that we do not escape completely like systemd

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

PVE/API2/Disks/Directory.pm

@@ -90,6 +90,8 @@ my $write_ini = sub {
 sub systemd_escape {
     my ($val) = @_;
 
+    # NOTE: this is not complete, but enough for our needs. normally all
+    # characters which are not alpha-numerical, '.' or '_' would need escaping
     $val =~ s/\-/\\x2d/g;
 
     return $val;