fix hostname of cobald slurm node

made cobald be able to run slurm jobs, previously failing with
permission denied.

roles/slurm/tasks/main.yml

@@ -67,7 +67,9 @@
     - slurm.conf
     - cgroup.conf
   vars:
-    alloc_nodes: "{{ [ slurm_prefix+'-submit1' ] + extra_nodes | default([])}}"
+    slurm_alloc_nodes_default:
+    - name: "{{slurm_prefix+'-submit1'}}"
+    alloc_nodes: "{{ slurm_alloc_nodes_default + extra_nodes | default([])}}"
   notify: reconfigure slurm
   tags: [ slurm-config ]