ERROR: unable to reserve port 443 for static PAT

The issue here is that the http service on the ASA is runnnig off of the standard port 80. Login to the firewall and run the following.

no http server enable

http server enable 8080

Now you should be able to add a NAT/PAT on port 443 to another server of your liking. Just remember when you attempt to use ASDM to manage the ASA in the future to specify the new port 8080.