设置为 null 减少不必要的判断

mybatis-plus-core/src/main/java/com/baomidou/mybatisplus/core/injector/AbstractMethod.java

@@ -66,7 +66,7 @@ public abstract class AbstractMethod implements Constants {
      */
     @Deprecated
     public AbstractMethod() {
-        methodName = "";
+        methodName = null;
     }
 
     /**