Fix #131 symfony error

Is this backwards compatibile? E.g. does data processor still work in Civi 5.27? There are still users around on older CiviCRM versions

@jaapjansma No probably won't work with 5.27. But without this it won't work with drupal 10 or anything that has symfony 4

Do you know from which version onwards this will work in CiviCRM? We can then update the line info.xml and remove older civicrm versions.

I see you already did a change to info.xml in !120 (merged)

mentioned in commit e263de98

merged