refactor(login): simplify mobile validation logic in login form

- Removed redundant mobile number validation check to streamline the login process.
- Maintained existing error handling for password input to ensure user feedback remains intact.

src/views/User/login.vue

@@ -363,12 +363,7 @@
                     this.setError('mobile', '请输入手机号');
                     return false;
                 }
-
-                if (!this.validateMobile(this.form.mobile)) {
-                    this.setError('mobile', '请输入正确的手机号');
-                    return false;
-                }
-
+                
                 if (!this.form.password) {
                     this.setError('password', '请输入登录密码');
                     return false;