添加验证码4位

src/main/java/com/unissoft/controller/PublicController.java

@@ -92,7 +92,7 @@ public class PublicController {
     @ApiOperation(value = "获取登录验证码")
     @GetMapping("/captcha")
     public ResultView captcha() {
-        SpecCaptcha specCaptcha = new SpecCaptcha(130, 48, 5);
+        SpecCaptcha specCaptcha = new SpecCaptcha(130, 48, 4);
         String verCode = specCaptcha.text().toLowerCase();
         String key = UUID.randomUUID().toString();
         // 存入redis并设置过期时间为3分钟