Removed bogus comma from feature_encoders.
Removed bogus comma from feature_encoders.

PiperOrigin-RevId: 163911814

vthorsteinsson/tensor2tensor,rsepassi/tensor2tensor,tensorflow/tensor2tensor,vthorsteinsson/tensor2tensor,vthorsteinsson/tensor2tensor,tensorflow/tensor2tensor,tensorflow/tensor2tensor,tensorflow/tensor2tensor,waterblue13/tensor2tensor,tensorflow/tensor2tensor,rsepassi/tensor2tensor,waterblue13/tensor2tensor,vthorsteinsson/tensor2tensor,rsepassi/tensor2tensor,waterblue13/tensor2tensor,rsepassi/tensor2tensor