=> Booting WEBrick => Rails 3.2.8 application starting in development on http://0.0.0.0:3000 => Call with -d to detach => Ctrl-C to shutdown server
[DEVISE] To select a encryption which isn't bcrypt, you should use devise-encryptable gem.
[2012-12-17 10:50:56] INFO WEBrick 1.3.1 [2012-12-17 10:50:56] INFO ruby 1.9.3 (2012-02-16) [x86_64-darwin11.4.0] [2012-12-17 10:50:56] INFO WEBrick::HTTPServer#start: pid=46243 port=3000
这个 devise 警告是什么原因?