.gdbinit: revert colored prompt
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39288 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
.gdbinit: revert colored prompt
work well with invisible sequence in prompt.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39288 b2dd03c8-39d4-4d8f-98ff-823fe69b080e