Fix mis-scaled signals for subject 018: divide by 1e6 (part 13/33 of full fix for subjects 004,005,008-035,058-060).

sourcedata/braindecode/dataset.zarr/recording_18/data/c/0/0/0

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:d792829b223c742a2a53b55f747b4114752eeee4d71cf94755b638a073e1a3e4
-size 18593209
+oid sha256:f4374e06106e50723516cf26c783ddf5be7bffd420483511482493ac4b95c150
+size 18588231

sourcedata/braindecode/dataset.zarr/recording_18/data/c/1/0/0

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:c42bd3fc805855860d3ed1463ee1754cd9d010c9948ac1ffafb3ea60d5be868b
-size 11622862
+oid sha256:28e644380ecf3b39b0157819ecfb29154453ab98f6a382e3db8672b4bb7f02d0
+size 11619434