* lib/drb/acl.rb: Removed meaningless #to_s methods in interpolation.
  [Feature #10174][ruby-core:64584]
* lib/erb.rb: ditto.
* lib/observer.rb: ditto.
* lib/rake/invocation_chain.rb: ditto.
* lib/rubygems/command_manager.rb: ditto.
* lib/rubygems/config_file.rb: ditto.
* lib/uri/common.rb: ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47299 b2dd03c8-39d4-4d8f-98ff-823fe69b080e