Don't replace server port by default

[APT-ZERO]

Hello Currently FlClash replaces subscription port with 7890 (this function is enabled by default!) It is not a good idea, on mobile phones, other apps can prevent user from connecting to VPN

for example v2rayNG uses a default port, other apps easily make user not be able to connect to any config and their users report it everyday, like this one https://github.com/2dust/v2rayNG/issues/3342