MT#7747 Make sure to not store purge_existing

lib/NGCP/Panel/Controller/API/BillingFees.pm

@@ -181,7 +181,7 @@ sub POST :Allow {
         }
 
         unless($data) {
-
+            delete $resource->{purge_existing};
             my $form = $self->get_form($c);
             my $zone;
 

lib/NGCP/Panel/Role/API/BillingFees.pm

@@ -87,6 +87,8 @@ sub fee_by_id {
 sub update_fee {
     my ($self, $c, $fee, $old_resource, $resource, $form) = @_;
 
+    delete $resource->{purge_existing};
+
     my $reseller_id;
     if($c->user->roles eq "admin") {
     } elsif($c->user->roles eq "reseller") {