Fix Postmoogle systemd service description

roles/custom/matrix-bot-postmoogle/templates/systemd/matrix-bot-postmoogle.service.j2

@@ -1,6 +1,6 @@
 #jinja2: lstrip_blocks: "True"
 [Unit]
-Description=Matrix helpdesk bot
+Description=Matrix Postmoogle bot
 {% for service in matrix_bot_postmoogle_systemd_required_services_list %}
 Requires={{ service }}
 After={{ service }}