spice-html5: hack to enable secure console

This is an horrible hack to fix spice-html5 code while this is fixed
upstream.

It aims to create a new parameter (false by default to maintain backward
compatibility) which enable or not secure console. If enabled, it will
replace the hardcoded "ws" to "wss" and then make the secure Spice
console working.

Closes-bug #604
Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>
Merge pull request #606 from enovance/spicehtml6-hack

spice-html5: hack to enable secure console