FIX: Remove unused ANTs param

Author: mgxd

nibabies/data/within_subject_t1t2.json

@@ -31,7 +31,6 @@
     [ 0.1, 3.0, 0.0 ]
   ],
   "transforms": [ "Translation", "Rigid", "SyN" ],
-  "use_estimate_learning_rate_once": [ false, false, true ],
   "use_histogram_matching": [ true, true, true ],
   "verbose": true,
   "winsorize_lower_quantile": 0.0001,