Compile-fix for removal of RequestClient.removeFrom()

The callback was removed in fred commit
f48c55bfba5e6255ffb7d8cb755e1833072d3a30.
WOT did not use the callback anyway, so this commit removes the
implementations without replacement.
Compile-fix missing implementation of getRequestClient()

The RequestClient getter callback was added in fred commit
ce57959a614e5767bf497f69e6b8608bb2707fdc
Compile-fix: Add missing implementation of onResume()

The callback was added in fred commit
fab462a7daff8a3a77ba1f90999a97383a87a157