Revert "licensing: add ISC as notice-required"

This reverts commit 8295f4267ab3791e083692f4781be04ce54e41ca.

Reason for revert: chromium:1155836

Original change's description:
> licensing: add ISC as notice-required
>
> BUG=None
> TEST=CQ passes
>
> Change-Id: I304417f7f034e237a41526d082338d21176c4851
> Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2570027
> Tested-by: Mike Frysinger <vapier@chromium.org>
> Commit-Queue: Mike Frysinger <vapier@chromium.org>
> Reviewed-by: Stephane Belmon <sbelmon@google.com>

BUG=chromium:1155836
TEST=CQ
TEST=cros tryjob -g 2576058 asurada-release-tryjob

Change-Id: Id908363b15fe55578fcc9dedabcb1e326d188c77
Exempt-From-Owner-Approval: Breaks all -release builders.
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/2576058
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Commit-Queue: Nicolas Boichat <drinkcat@chromium.org>
Tested-by: Nicolas Boichat <drinkcat@chromium.org>
Auto-Submit: Nicolas Boichat <drinkcat@chromium.org>
diff --git a/licensing/licenses_lib.py b/licensing/licenses_lib.py
index e4eff85..81e4e0a 100644
--- a/licensing/licenses_lib.py
+++ b/licensing/licenses_lib.py
@@ -134,11 +134,10 @@
 # attribution from them.
 COPYRIGHT_ATTRIBUTION_LICENSES = [
     'BSD',    # requires distribution of copyright notice
-    'BSD-2',  # so does BSD-2 https://opensource.org/licenses/BSD-2-Clause
-    'BSD-3',  # and BSD-3? https://opensource.org/licenses/BSD-3-Clause
+    'BSD-2',  # so does BSD-2 http://opensource.org/licenses/BSD-2-Clause
+    'BSD-3',  # and BSD-3? http://opensource.org/licenses/BSD-3-Clause
     'BSD-4',  # and 4?
     'BSD-with-attribution',
-    'ISC',    # so does ISC https://opensource.org/licenses/ISC
     'MIT',
     'MIT-with-advertising',
     'Old-MIT',