If the distribution wizard has already started on a wiki on which batch install is done, the batch installed is failing with an error

This issue concerns the functionality that allows to batch install an extension on multiple wikis, added by EXTWEAK-2, in the following case:

• when the option "Try to finalize the DW if any is found running on the wiki" is checked
• when a subwiki from the ones configured had already been accessed (and distribution wizard started on it).

If this is the case, the batch installer will fail with a groovy exception complaining that the property "State" does not exist for class org.xwiki.contrib.extensiontweak.EMInstallService .

This reproduces on XWiki 6.4.8 .