fix: 判断短信发送成功字符串错误

src/main/java/nju/seec/helper/util/SmsUtils.java

@@ -20,7 +20,7 @@ import org.springframework.stereotype.Component;
 @Component
 @Slf4j
 public class SmsUtils {
-    private static final String OK = "ok";
+    private static final String OK = "OK";
     private final SmsProperties smsProperties;
 
     public SmsUtils(SmsProperties smsProperties) {