fix grammar

Author: aldehir

common/chat.cpp

@@ -1326,7 +1326,7 @@ static common_chat_params common_chat_params_init_gpt_oss(const common_chat_temp
                 builder.resolve_refs(parameters);
 
                 tool_rules.push_back(builder.add_rule(name + "-call",
-                    "\"" + name + "\"" + " space* \"<|constrain|>\"? \"json<|message|>\" " + builder.add_schema(name + "-args", parameters)
+                    "\"" + name + "\"" + " space \"<|constrain|>\"? \"json\" space \"<|message|>\" " + builder.add_schema(name + "-args", parameters)
                 ));
             });