Editing text fields in rapid succession causing Sketch to crash (Sketch 51 [57462], Paddy 1.0.7)
### Bug report
#### Expected behavior:
- Edit a text field that exists inside a group or art board with spacing settings in its name (e.g. "artboard_name [0v]")
- Finish editing (hit cmd + enter)
- Text edit is completed and layers readjust accordingly


#### Actual behavior:
- Sketch crashes when finishing edits to a text field (hitting cmd + enter), when Paddy is recalculating layout
- Crash seems to happen at random after at least 1-2 previous edits on other text fields, sometimes after more like 8-10 edits on previous text fields

#### Steps to reproduce:
- Create an art board with a name like "art board [0v]"
- Create 13 text fields inside this art board (combo of fixed and auto sizes) organized vertically down
- Start editing the text of each text field, one after another

#### Notes
Unsure if this is a Paddy issue or an issue with newest version of Sketch, but the crash seems to stop if I remove the "[0v]" from the art board's name