UserAgreementFilter:doFilterInternal - obtain context only if required

[saschaszott]

Minor improvement of method UserAgreementFilter:doFilterInternal.

[abollini]

change looks good and ok but there is a test failure, we should check if it is a random unrelated issue

[saschaszott]

@jor4science, this is not production-critical but easy to merge.

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[saschaszott]

@jor4science , do you have any updates on this issue?