Don't apply wiki, forum and ldap changes with missing credentials

This makes setting up your own version of kninfra a lot easier.
Now properly detect whether an activity is new in the template
Give a warning when there are no credentials available for the daemons
Merge pull request #246 from aykevl93/ignore-unused-credentials

Negeer wiki, forum en/of ldap als er geen credentials zijn ingesteld
Merge pull request #248 from aykevl93/subscription-edit-template

Fix voor #244