Templating: Only use wsrep_provider_options when galera_extra_wsrep_p…

…rovider_options is defined

templates/etc/mysql/conf.d/galera.cnf.j2

@@ -72,7 +72,9 @@ wsrep_notify_cmd='{{ galera_monitor_script_path }}/{{ galera_monitor_script_name
 
 wsrep_node_address="{{ galera_wsrep_node_address }}"
 
+{% if galera_extra_wsrep_provider_options is defined %}
 wsrep_provider_options = "{% for item in galera_extra_wsrep_provider_options %}{% set _key = item.split(': ')[0] %}{% set _val = galera_extra_wsrep_provider_options[_key] %}{{ _key }} = {{ _val }}{% if not loop.last %}; {% endif %}{% endfor %}"
+{% endif %}
 
 [sst]
 {% if mariadb_tls_files and mariadb_tls_files|length == 3 and galera_sst_tls_enabled  %}