remove useless header

Signed-off-by: Yiheng Wang <[email protected]>

Author: yiheng-wang-nv

monai/data/image_reader.py

@@ -1088,7 +1088,7 @@ def get_data(self, img):
         data_shape = header.get_data_shape()
         data_dtype = header.get_data_dtype()
         affine = header.get_best_affine()
-        meta = dict(header)
+        meta = {}
         meta[MetaKeys.AFFINE] = affine
         meta[MetaKeys.ORIGINAL_AFFINE] = affine
         # TODO: as_closest_canonical