3.5.1 Only check for AS3CF remove local setting if plug-in is active

[tijmenbruggeman]

A user reported an issue where they would get an error when loading the Tinify settings page. This happened on the check if AS3CF would remove files locally. The request is done on the plug-in settings page to render a warning and only happens if the plug-in AS3CF is active.

Internally get_option would return null. This option should not return null as it contains all the settings for AS3CF. Nonetheless it returned null so there is a case where the user has not set any settings yet but has the plug-in activated.

Therefor I've added a check to see if the get_option returns a valid value.

• Added a check to verify if the plug-in is active
• Check if the plug-in option exists
• Added debug script for unit tests
• Added unit tests for AS3CF compatibility