Clean-up OSGi imports

[mattrpav]

wicket-datetime has import java.*

Need to add rules (and maybe others):
!java*,!kotlin*,*

[reckart]

@mattrpav Would you like to provide a PR to fix this?

[mattrpav]

Can you assign the task to me so it shows up on my GH todo's?

[reckart]

@solomax or @martin-g probably can.

[martin-g]

Assigned it to @mattrpav !