Loading get_flash_player.gif raises security warning when using https

0. Confluence runs in https-only-environment
0. attach PDF to page
1. click on "view" for attached pdf
2. flash-player is loaded. Code for fall-back reads:

<div>You need flash player installed to preview ppt and pdf files</div>
<div>		
 <p><a href="http://www.adobe.com/go/getflashplayer"><img src="http://www.adobe.com/images/shared/download_buttons/get_flash_player.gif" alt="Get Adobe Flash player" /></a></p>
</div>

3. browser raises security warning because of get_flash_player.gif is loaded via http from adobe.com

Proposed solution:

• Include gif in plugin-jar
• don't use external references to adobe as this addidionally could raise issues with referrer data and data privacy

Related:

• TGCMLS-12