优化代码，消除当独引入模块的情况下的bug

Author: imtzc

mybatis-plus-ext-core/mybatis-plus-ext-base/src/main/java/org/dromara/mpe/base/EntityScanner.java

@@ -17,7 +17,7 @@
 //@Component
 public class EntityScanner implements ApplicationListener<ContextRefreshedEvent> {
 
-    @Autowired
+    @Autowired(required = false)
     private List<IEntityRegister> entityRegisters;
 
     @Override