Improve SVR configuration space

[mfeurer]

Apparantly, the following configuration is in the meta-data:

  data_preprocessing:categorical_transformer:categorical_encoding:__choice__, Value: 'no_encoding'
  data_preprocessing:categorical_transformer:category_coalescence:__choice__, Value: 'no_coalescense'
  data_preprocessing:numerical_transformer:imputation:strategy, Value: 'median'
  data_preprocessing:numerical_transformer:rescaling:__choice__, Value: 'minmax'
  feature_preprocessor:__choice__, Value: 'polynomial'
  feature_preprocessor:polynomial:degree, Value: 2
  feature_preprocessor:polynomial:include_bias, Value: 'True'
  feature_preprocessor:polynomial:interaction_only, Value: 'False'
  regressor:__choice__, Value: 'libsvm_svr'
  regressor:libsvm_svr:C, Value: 180.22479438529933
  regressor:libsvm_svr:degree, Value: 4
  regressor:libsvm_svr:epsilon, Value: 0.0012571604901280202
  regressor:libsvm_svr:gamma, Value: 0.10272820821863678
  regressor:libsvm_svr:kernel, Value: 'rbf'
  regressor:libsvm_svr:max_iter, Constant: -1
  regressor:libsvm_svr:shrinking, Value: 'False'
  regressor:libsvm_svr:tol, Value: 0.02945259690926852

I don't think it should have a degree for the rbf kernel.