Marginalization with delta function prior

I was performing BNS injections with fixed geocent_time, and had also set time-marginalization=True in the config. The sampling failed to start and the jobs were killed after 8 hours. Setting time-marginalization=False and re-running solved the problem.

Since it doesn't make sense to marginalize over a parameter when the parameter is fixed, it would be nice to have a test to check when <param>-marginalization=True and param is fixed.