Fix phpMyAdmin stack upgrade

* improve install script

wo/cli/plugins/stack_upgrade.py

@@ -7,10 +7,11 @@ from wo.core.apt_repo import WORepo
 from wo.core.services import WOService
 from wo.core.fileutils import WOFileUtils
 from wo.core.shellexec import WOShellExec
-from wo.core.git import WOGit
+from wo.core.extract import WOExtract
 from wo.core.download import WODownload
 import configparser
 import os
+import shutil
 
 
 class WOStackUpgradeController(CementBaseController):