add Style/BlockComments to .rubocop.yml

git-svn-id: http://svn.redmine.org/redmine/trunk@20646 e93f8b46-1217-0410-a6f0-8f06a7374b81

.rubocop.yml

@@ -133,6 +133,11 @@ Style/AsciiComments:
     # We can not change nor remove it.
     - 'app/models/repository/git.rb'
 
+Style/BlockComments:
+  Enabled: true
+  Exclude:
+    - 'lib/diff.rb'
+
 Style/BlockDelimiters:
   Enabled: true
   Exclude: