server : add system_fingerprint to chat/completion (#10917)

* server : add system_fingerprint to chat/completion

* update README

examples/server/utils.hpp

@@ -56,6 +56,8 @@ static T json_value(const json & body, const std::string & key, const T & defaul
     }
 }
 
+const static std::string build_info("b" + std::to_string(LLAMA_BUILD_NUMBER) + "-" + LLAMA_COMMIT);
+
 //
 // tokenizer and input processing utils
 //