BF: Use a writeable bytearray for the header data.

This is because newer numpy doesn't allow to change the writeable flag.

Author: arokem

nibabel/streamlines/trk.py

@@ -559,8 +559,8 @@ def _read_header(fileobj):
 
             # Read the header in one block.
             header_str = f.read(header_2_dtype.itemsize)
-            header_rec = np.frombuffer(buffer=header_str, dtype=header_2_dtype)
-            header_rec.setflags(write=1)
+            header_rec = np.frombuffer(buffer=bytearray(header_str),
+                                       dtype=header_2_dtype)
             # Check endianness
             endianness = native_code
             if header_rec['hdr_size'] != TrkFile.HEADER_SIZE: