Only trigger interrupt on `Esc` when interrupt button visible

[catboxanon]

Description

Fixes an issue where if the Esc key is pressed and no lightbox modal is on screen, it will lock up the UI by triggering an interrupt when it shouldn't.

Closes this issue here: https://github.com/lllyasviel/stable-diffusion-webui-forge/issues/89

Checklist:

• [x] I have read contributing wiki page
• [x] I have performed a self-review of my own code
• [x] My code follows the style guidelines
• [x] My code passes tests