fixed typo in call to renameFile closure

When using lazybones create griffon-plugin, I got

"Post install script caused an exception, project might be corrupt:
No signature of method: lazybones.renamefile() is applicable for
argument types: (java.io.File, java.lang.String) values:
[foo/subprojects/plugin/src/main/java/Module.java,
/home/tobias/tmp/foo/subprojects/plugin/src/main/java/org/codehaus/griffon/runtime/foo/FooModule.java]"
fixes #31