[Bug] Send Email - Same file is already selected + Uploading Plugin from wp.org generates PHP notice

[Rat01047]

Issue-1:
When a Upload File is chosen > Click Add More Files > The same file is already selected

Scenario:
Subscribe 2 > Send Email > Click > Upload File > Upload/Attach a file > Click on Upload File again > The 2nd(new) Upload option already has the previous uploaded file selected

Video for reference:
https://www.awesomescreenshot.com/video/13240279?key=8d604af8ab0b05b559737dbb9ef81ca5

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Issue-2:
Uploading a Plugin/Zip after downloading from Wordpress.org > a Php notice is found in Debug.log

Scenario:
Download Subscribe2 Plugin Zip from Wordpress.org > Go to Plugins Page > Add New and Upload Plugin > PHP notice is found in Debug Log

Debug Log error:

[23-Dec-2022 06:55:18 UTC] PHP Notice:  Undefined variable: wp_version in /home/ratul/ratul.ajaira.website/public/wp-content/plugins/subscribe2/uninstall.php on line 12
[23-Dec-2022 06:55:18 UTC] PHP Notice:  Undefined variable: s2_mu in /home/ratul/ratul.ajaira.website/public/wp-content/plugins/subscribe2/uninstall.php on line 20