* lib/net/imap.rb (capability_response): should ignore trailing
  spaces.  Thanks, Peter Kovacs.  [ruby-core:55024] [Bug #8415]

* test/net/imap/test_imap_response_parser.rb: related test.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41091 b2dd03c8-39d4-4d8f-98ff-823fe69b080e