Fix view.js to properly mark cancelled tasks

[CryptoRhinoGH]

Fixed view.js script to properly mark cancelled tasks compared to highlighted tasks with tasks plugin

Earlier view.js was checking if a script is cancelled or not based on task.completed == true and task.checked == true, but dv returns .checked == true in the case

Whether or not this task status is empty, meaning it has a space in its [ ] brackets
Dataview Docs - Tasks Metadata

By default cancelled task is denoted by - [-], compared to other options like - [!], - [^] and so on are incorrectly marked as cancelled.

Added check for status instead of checked