Cannot read property 'substring' of undefined

[nfillon]

To Reproduce
Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

VSCodeVim version: 1.22.1

Stack trace

TypeError: Cannot read property 'substring' of undefined
    at C.display (/Users/fillonnicolas/.vscode/extensions/vscodevim.vim-1.22.1/src/cmd_line/commandLine.ts:223:21)
    at statusBarText (/Users/fillonnicolas/.vscode/extensions/vscodevim.vim-1.22.1/src/statusBar.ts:205:35)
    at Object.clear (/Users/fillonnicolas/.vscode/extensions/vscodevim.vim-1.22.1/src/statusBar.ts:105:17)
    at /Users/fillonnicolas/.vscode/extensions/vscodevim.vim-1.22.1/extensionBase.ts:354:23
    at runMicrotasks (<anonymous>)
    at processTicksAndRejections (internal/process/task_queues.js:93:5)

[J-Fields]

Duplicate of #7512