Skip summarize when not triggered via slash cmd and can't summarize

Maybe better to fallback to non-summarize behavior if summarize intent
is just inferred but we can't actually summarize because the single
file added to conversation isn't satisfied

src/khoj/processor/conversation/openai/gpt.py

@@ -154,7 +154,7 @@ def converse(
         completion_func(chat_response=prompts.no_online_results_found.format())
         return iter([prompts.no_online_results_found.format()])
 
-    if ConversationCommand.Online in conversation_commands or ConversationCommand.Webpage in conversation_commands:
+    if not is_none_or_empty(online_results):
         conversation_primer = (
             f"{prompts.online_search_conversation.format(online_results=str(online_results))}\n{conversation_primer}"
         )