Clarify HTTP/HTTPS client outproxy configuration

[ihave2p]

1) Clarify the need to enter same proxy twice *OR* eliminate that need

• HTTP/HTTPS Client: if the outproxy serves both http+https simultaneously, add a note in the UI that the outproxy must be entered in both "Outproxies(x):" *and* "SSL Outproxies:" . If only the http field is filled and a subsequent https site is requested, the tunnel will respond with a confusing error and drop attempts to access https (see 2)

2) Change/remove error response to clarify the need for 1)

• The following is returned despite being properly configured for http ("SSL Outproxies:" field is empty and https is requested):

"Warning: No Outproxy Configured

Your request was for a site outside of I2P, but you have no HTTP outproxy configured. Please configure an outproxy in I2PTunnel.

I2P HTTP Proxy Server"