WebAgent override Request URL does not takes X-Forwarded-Host may have port.

Problem

When using Override Request URL Host enabled and if there is any front end LB that sets X-Forwarded-Host, it seems that the Webagent generated override_url is very strict. The issue here is that the standard definition of "X-Forwarded-Host" is not so well defined to have a port or if this is a "Host" header. Many interpretation see Mozilla , Microsoft https://docs.microsoft.com/en-us/aspnet/core/host-and-deploy/proxy-load-balancer and other github projects and it is clear this is an unsettle issue and left to the new Forwarded header)/

Now the issue is that for frontend LB that generates the X-Forwarded-Host: <server>:<port> the Webagent will generate the following override_url "<server>:<port>:<port>" for the redirect_uri and is an invalid URL

Testcase:

• Test Webagent with override host with incoming request with X-Forwarded-Host with host:port pair.

Cause

• The host variable before serialise_url should ensure when forming URL that the host does not have ":" (or if the port is not -1/empty or it is used).
• One should trim or avoid wrongly generated URL wih duplicate ":" that cause redirect_uri issues.