Drop ACM license.

git-svn-id: https://svn.r-project.org/R/trunk@88261 00db46b3-68df-0310-9c12-caf00c1e9a41

Author: hornik

share/licenses/license.db

@@ -306,12 +306,3 @@ OSI: open (https://opensource.org/licenses/BSL-1.0)
 URL: http://www.boost.org/LICENSE_1_0.txt
 FOSS: yes
 SPDX: BSL-1.0
-
-Name: ACM Software License Agreement
-Version: 1998
-Abbrev: ACM
-URL: https://www.acm.org/publications/policies/software-copyright-notice
-FOSS: no
-Restricts_use: yes
-Note: Only appropriate for packages containing pre-2013 ACM code or
- depend on others which do.