tmux integration hangs when logged in with mosh (ok w/ ssh)

Thanks for filing an issue! Please answer the questions below so I can help you.

• iTerm2 version: 3.0.15
• OS version: OS X 10.11.6
• Attach ~/Library/Preferences/com.googlecode.iterm2.plist here (drag-drop from finder into this window)com.googlecode.iterm2.plist

Detailed steps to reproduce the problem:

1. Use mosh 1.26 to log into remote system
2. tmux -CC

What happened: No menu of options shown. Esc, X, L, C are not echoed and have no apparent effect. Tmux options in Shell menu are all grey. Pane becomes completely unresponsive. Have to close pane using the 'x' icon in the title bar.

What should have happened: Menu of options + New tmux window as described in docs. Things work as expected when I log into the remote server with ssh instead of mosh. Remote is running tmux version 1.9