[Plugin: WordPress HTTPS (SSL)] Cannnot save changes

I am still using wp 3.2.1
and was using https plugin with version 1.9.2 this way:

WP is installed and running under this domain (apache vhost):
https://www.computersalat.de/

backend is secured via a “sharedssl-host” “https://sharedssl.wwserver.net/cs-wp/” (apache default vhost).
In docroot of shared sslhost there is symlink “cs-wp” which points to docroot of vhost “www.computersalat.de”. (cs-wp -> ../vhosts/csalat/html/)

Now I tried to update HTTPS to 3.0.4 setting “SSL Host” to “cs-wp -> ../vhosts/csalat/html/”, but then when trying to save it is saying
– Invalid WordPress installation at https://sharedssl.wwserver.net/cs-wp/

so HTTPS is completly broken and unusable.
Where did the “sharedssl_host config gone ?
Why are there still “unused” settings in database from older installs, why did they not get removed ?

https://www.ads-software.com/extend/plugins/wordpress-https/