[BUG] config: fix erroneous check on cookie domain names, again

The previous check was correct: the RFC states that it is required
to have a domain-name which contained a dot AND began with a dot.
However, currently some (all?) browsers do not obey this specification,
so such configuration might work.

This patch reverts 3d8fbb6658d4414dac20892bbd9e79e14e99e67f but
changes the check from FATAL to WARNING and extends the message.
1 file changed