ターミナルを起動すると、必ずsshで特定のサーバに接続しようとしてしまうようになった。
原因と解決方法は、以下。

Q: Whenever I open the Terminal, it tries to connect to a ssh host - what's going on?
A: Looks like you have clicked "Use settings as default" in the Terminal's window settings. Terminal saves the opening command there too. Go to /Users/[yourname]/Library/Preferences and remove/edit the file called com.apple.Terminal.plist

grepsoft.net - JellyfiSSH support