Update calculation of `trunk_suffix`

geant/gap_ansible/roles/iptrunk/templates/juniper/trunk_interface.j2

@@ -25,7 +25,10 @@
     {# I need to sort the source and the destination alfabetically #}
     {% set trunk_direction_name = [ local.name.split(".")[1] | upper, remote.name.split(".")[1] | upper ] %}
     {% set trunk_direction_name_sorted = trunk_direction_name|sort %}
+
+    {% if wfo_trunk.iptrunk.iptrunk_description_suffix is not none %}
     {% set trunk_suffix = '-'+wfo_trunk.iptrunk.iptrunk_description_suffix if wfo_trunk.iptrunk.iptrunk_description_suffix|length > 0 %}
+    {% endif %}
     {##}
     interfaces {
     replace: {{local.ae_name}} {