duplicate items when registering the branch

• I have searched the issues of this repository and believe that this is not a duplicate.

Ⅰ. Issue Description

lockKeys have the duplicate items, like this:
lockKeys = ci_73_978_njrs:307;ci_73_978_njrs:307,308;ci_73_978_njrs:307,308,309,310,311;ci_73_978_njrs:307,308,309,310;ci_73_978_njrs:307,308,309,310,311,312;ci_73_978_njrs:307,308,309,310,311,312,313,314;ci_73_978_njrs:307,308,309,310,311,312,313;ci_73_799_pjct:14;trigger_tasks_73:167470;ci_73_978_njrs:307,308,309;trigger_task_change_logs_73:150222

Ⅱ. Describe what happened

when the @Transactional is under the @GlocalTransactional, and the method is called recursively in many hierarchies

Ⅲ. Describe what you expected to happen

lockKeys should be:
lockKeys = ci_73_978_njrs:309;ci_73_978_njrs:307;ci_73_978_njrs:308;ci_73_978_njrs:314;ci_73_978_njrs:312;trigger_tasks_73:167471;ci_73_978_njrs:313;ci_73_978_njrs:310;ci_73_799_pjct:14;ci_73_978_njrs:311;trigger_task_change_logs_73:150223

Ⅳ. How to reproduce it (as minimally and precisely as possible)

mybatis配置使用
configuration:
default-executor-type: reuse

Ⅴ. Anything else we need to know?

Ⅵ. Environment:

• JDK version :
• seata : 1.2.0
  mybatis-spring-boot-starter: 2.1.0

Start by reproducing the issue with Seata 1.2.0, MyBatis Spring Boot Starter 2.1.0, and default-executor-type: reuse, using nested @GlobalTransactional and @Transactional calls with recursive invocation. Trace branch registration and lockKeys assembly to determine where repeated entries are introduced. Done means the reproduced case produces the expected unique lockKeys without duplicate items.