So I've installed OwnCloud on my Raspberry Pi and I'm able to use it properly on my LAN. Now the problem is when I want to access it from the WAN. I've set port forwarding [port 80 to port 80] & [port 443 to port 443] to the static local IP of my Pi. I've went to canyouseeme.org on my Pi and I've seen that port 80 and 443 are open. Although, when I type my external IP in the address bar of my browser, I get "400 Bad Request".
The problem is that in the configuration file of Apache2 on my Pi, it is set to host on "localhost port 80"
What do I have to change in the configuration file to be able to access my pi on the WAN?
Any help is greatly appreciated :)