dhcp_server.py: bugfix pool assignment

Commit 91c3b8bdd9 ("dhcp_server.py: cleanup") did not only cleanup parts
of the code but in addition added support for DHCP failover. That support
could lead to an empty pool {} statement if the subnet declaration only had
static address assignments but no range at all.

  ---<snip>---
  dhcpd: /etc/dhcp/dhcpd.conf line 70: Pool declaration with no address
  range.
  dhcpd:         }
  dhcpd:          ^
  dhcpd: Pool declarations must always contain at least
  dhcpd: one range statement.
  ---</snip>---

1 files changed, 6 insertions, 2 deletions

diff --git a/src/conf_mode/dhcp_server.py b/src/conf_mode/dhcp_server.py
index a26e4626a..2a2b1fe6c 100755
--- a/src/conf_mode/dhcp_server.py
+++ b/src/conf_mode/dhcp_server.py
@@ -195,15 +195,19 @@ shared-network {{ network.name }} {
         }
         {%- endif %}
         {%- endfor %}
+        {%- if subnet.failover_name %}
         pool {
-            {%- if subnet.failover_name %}
             failover peer "{{ subnet.failover_name }}";
             deny dynamic bootp clients;
-            {%- endif %}
             {%- for range in subnet.range %}
             range {{ range.start }} {{ range.stop }};
             {%- endfor %}
         }
+        {%- else %}
+        {%- for range in subnet.range %}
+        range {{ range.start }} {{ range.stop }};
+        {%- endfor %}
+        {%- endif %}
     }
     {%- endfor %}
     on commit { set shared-networkname = "{{ network.name }}"; }