Incorrect URL for XAR file in wikis created by XEM

The URL for the XAR to import is incorrect for xwiki created in a farm. Say one has installed XEM 1.6.2 and created a wiki named 'testwiki.xwiki.example.com' the URL in "http://testwiki.xwiki.example.com:8080/xwiki/bin/import/XWiki/XWikiPreferences" points to:

http://maven.xwiki.org/releases/com/xpn/xwiki/products/xwiki-enterprise-wiki/1.6.2/xwiki-enterprise-wiki-1.6.2.xar

It should point to:

http://maven.xwiki.org/releases/com/xpn/xwiki/products/xwiki-enterprise-wiki/1.8.2/xwiki-enterprise-wiki-1.8.2.xar

Somehow the XWikiPreferences should detect whether the wiki is part of a farm and handle the "off-by-two" versioning of XEM, although i fail to see how it would be able to do so ...