replace origin mybatis-generator-core 1.3.6 in your local repository with this.
Then regenerated using maven plugin 1.3.6
It will not override the existing content,only add the content you delete.
If your mybatis-generator-version is not v1.3.6,download source code,change version in pom.xml and install on your local repository.
If you mybatis-generator-version is too old to be compatible with v1.3.6,suggestion is switch to new version,or you can change old version's source code.
I have mark "todo" on what I modified in source code, if you open it in idea,this can give you a little help if you want to modify source code.