fix: Allow next_hop_gateway to be passed for non-internet routes (#242)

Author: drebes

modules/routes-beta/main.tf

@@ -28,7 +28,7 @@ resource "google_compute_route" "route" {
   description            = lookup(var.routes[count.index], "description", null)
   tags                   = compact(split(",", lookup(var.routes[count.index], "tags", "")))
   dest_range             = lookup(var.routes[count.index], "destination_range", null)
-  next_hop_gateway       = lookup(var.routes[count.index], "next_hop_internet", "false") == "true" ? "default-internet-gateway" : ""
+  next_hop_gateway       = lookup(var.routes[count.index], "next_hop_internet", "false") == "true" ? "default-internet-gateway" : null
   next_hop_ip            = lookup(var.routes[count.index], "next_hop_ip", null)
   next_hop_instance      = lookup(var.routes[count.index], "next_hop_instance", null)
   next_hop_instance_zone = lookup(var.routes[count.index], "next_hop_instance_zone", null)