icingaweb2: run pqslcmd with LANG=C to ensure the output is in english

* fix run pqslcmd with LANG=C to ensure the output is in english and we can match for '(0 rows)' in the next task (#241)

roles/icingaweb2/tasks/manage_icingaweb_pgsql_db.yml

@@ -45,6 +45,7 @@
   block:
     - name: PostgreSQL check for icingaweb admin user
       ansible.builtin.shell: >
+        LANG=C
         {{ _tmp_pgsqlcmd }}
         -w -c "select name from icingaweb_user where name like '{{ icingaweb2_admin_username }}'"
       failed_when: false