Redundant Parameter Initialization in the bns_eos_example.py example code

When run as is, the bns_eos_example.py sample code returns the following relevant warning and error output:

15:05 bilby WARNING : {'chirp_mass', 'symmetric_mass_ratio'} already in prior. This may lead to unexpected behaviour. 15:05 bilby WARNING : mass_ratio is a redundant key in this BNSPriorDict. 15:05 bilby WARNING : {'mass_ratio', 'symmetric_mass_ratio'} already in prior. This may lead to unexpected behaviour. 15:05 bilby WARNING : chirp_mass is a redundant key in this BNSPriorDict. 15:05 bilby WARNING : {'chirp_mass', 'mass_ratio'} already in prior. This may lead to unexpected behaviour. 15:05 bilby WARNING : symmetric_mass_ratio is a redundant key in this BNSPriorDict.

bilby.core.sampler.base_sampler.IllegalSamplingSetError: Your sampling set contains redundant parameters.

I believe that not initializing these redundant priors should solve this issue.