By the way, when we’re talking about solutions: Why don’t you just use a host name with only digits, letters and -, as recommended in the DNS standards? To me, this sounds easier and more compatible (also with other applications) than working around years-old Android 4.0.4 behavior with the risk of introducing other problems.
Add support for Server Name Indication (SSL protocol extension)
Many private servers host multiple domains with different ssl certificates. In order to be able to use davdroid with those servers needs davdroid needs to implement the Server Name Indication instead of the classical SSL protocol: http://wiki.apache.org/httpd/NameBasedSSLVHostsWithSNI
Dup of #9