Include port when using changeOrigin

[magicalhobo]

According to the HTTP spec, the port needs to be included in the host header if it's not the default port. It can be included even if it is the default port, so the easiest thing to do is always include it.

[jcrugzz]

@magicalhobo thanks for the contribution! Unfortunately we cannot make this assumption because the host property itself can include the port. (see how the url module behaves.) There will need to be something that better fits the type of inputs we get from a user.

[jcrugzz]

@magicalhobo you can see the fix I made above, just want to make sure it works as expected in all cases