create from project with resources plugin

when i run:mvn archetype:create-from-project with one of my project,it give me a warning :[WARNING] Using platform encoding (GBK actually) to copy filtered resources, i.e. build is platform dependent!
At first,i thougt i have wrong maven-resources-plugin in pom,but when i run mvn install, it's ok without the error.I find that when i run mvn archetype:create-from-project,the maven-resources-plugin's version is 2.7,but when i run mvn install ,it was 2.6. It's interesting for me,so i run mvn help:effective-pom, the version is still 2.6. I don't understand why the version is different and what should i do to remove the warning. Thank you!