Moved all setPostThumbnailL10n string calls to wp.i18n calls to match…

[szczys]

This works but it needs to be reviewed by the plugin author as I do not have any deep knowledge of the changes made. As mentioned in #146 it looks like Wordpress changed the method of accessing strings that was used by this plugin. I took what Wordpress core used for these messages in set-post-thumbnail.js and used them in the plugin.

… what's found in WordPress 5.5. core updates:

WordPress/WordPress@4377e9a#diff-4bfa11da57ff2600004bb500368247f4

[aliciaduffy]

This fixed the plugin for us in WordPress 5.5

[oliverands]

I've installed this version, and unfortunately it didn't resolve the issue for us in WordPress 5.5. Still not able to assign a second thumbnail to posts.

[ricdva]

This appears to be working correctly for me. I manually edited the multi-post-thumbnails-admin.js with these changes, just had to make sure the local browser cache was cleared and the new JS file was loading.

[oliverands]

Ah, that was it! Needed to clear the cache. It's working fine now. Thank you.

[undermeadow]

Just joined to thank for this solution and for the cache fix, ended up working perfectly and solved a huge issue for us.

[twentyfortysix]

Works for me too

[kasparsd]

Fixes #146 similar to #147.

[kasparsd]

The only potential issue with this is that the new helper methods are not available in older versions of WP. Ideally, we could add a dedicated helper method that picks the right method for printing strings.

[szczys]

Closing this as outdated.