fix: use try to set default for server list (#7)

Reviewed-on: #7
Co-authored-by: Robert Kaussow <mail@thegeeklab.de>
Co-committed-by: Robert Kaussow <mail@thegeeklab.de>

main.tf

@@ -1,7 +1,7 @@
 locals {
   ipv4_addresses = {
     for server_key, server in var.server : server.name => flatten([
-      for k, v in coalescelist(proxmox_virtual_environment_vm.server[server.name].ipv4_addresses, []) :
+      for k, v in try(proxmox_virtual_environment_vm.server[server.name].ipv4_addresses, []) :
       v if length(regexall(try(server.netif_filter, var.server_netif_filter), proxmox_virtual_environment_vm.server[server.name].network_interface_names[k])) > 0
     ])
   }
@@ -10,7 +10,7 @@ locals {
 locals {
   ipv6_addresses = {
     for server_key, server in var.server : server.name => flatten([
-      for k, v in coalescelist(proxmox_virtual_environment_vm.server[server.name].ipv6_addresses, []) :
+      for k, v in try(proxmox_virtual_environment_vm.server[server.name].ipv6_addresses, []) :
       v if length(regexall(try(server.netif_filter, var.server_netif_filter), proxmox_virtual_environment_vm.server[server.name].network_interface_names[k])) > 0
     ])
   }