Fix mis-scaled signals for subject 021: divide by 1e6 (part 16/33 of full fix for subjects 004,005,008-035,058-060).

sourcedata/braindecode/dataset.zarr/recording_21/data/c/0/0/0

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:cce3f5ce537228191ba1512e3459e0e460a50a1009bab044e52fa29e043da2b7
-size 18498456
+oid sha256:421af5671f89505b6a6c247fadda0d1b3bf69264dc244449b29f80faf758906c
+size 18494194

sourcedata/braindecode/dataset.zarr/recording_21/data/c/1/0/0

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:fc21881d3e423ada92a30a915fbc9e508a1944ea3e8f482afe2daf4d6f4ee337
-size 11575387
+oid sha256:9370793b64918cd8bdc4347ccf88a29ee158f5dd79da37c29a64808a371626b0
+size 11572987