[Try] endless crashing loop

[Huxpro]

Intro

Interestingly, the Try tab could fall into an endless loop of crashing.

Reproduce step

1. open https://reasonml.github.io/en/try?rrjsx=true&reason=DYUwLgBAhhBcEEsB2kC8ECMBnA3AKCA. This represent source code let a : int = 1s; (which is a typo I incidentally typed).
2. see try.js:44270 Uncaught TypeError: Cannot destructure property 'startLine' of 'undefined' as it is undefined. in your console.
3. now if you open just https://reasonml.github.io/en/try, it will try to restore the state from local storage and cause the try page crash again.