Update chat_template.jinja

Typo in chat template causes unexpected newline prefix when providing a system message.

chat_template.jinja

@@ -15,7 +15,7 @@
     <|im_assistant|>{{role_name}}<|im_middle|>
   {%- else -%}
     <|im_system|>{{role_name}}<|im_middle|>
-  {% endif %}
+  {%- endif -%}
 
   {%- if message['role'] == 'assistant' and message.get('tool_calls') -%}
     {%- if message['content'] -%}{{ message['content'] }}{%- endif -%}