fix testcase expecting incorrect remove log from dpkg

fix testcase expecting incorrect remove log from dpkg

dpkg 1.18.11 includes:
  * Do not log nor print duplicate dpkg removal action. We print
    “Removing <package> (<version>)” lines and log remove action twice
    when purging a package from frontends, because they usually first call
    --remove and then --purge sequentially. When purging a package which is
    already in config-files (i.e. it has been removed before), do not print
    nor log the remove action.