servers created from command-line should have tcp_only default mode

fixes #670

Cargo.lock

@@ -1623,7 +1623,7 @@ dependencies = [
 
 [[package]]
 name = "shadowsocks-rust"
-version = "1.12.0"
+version = "1.12.1"
 dependencies = [
  "build-time",
  "byte_string",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "shadowsocks-rust"
-version = "1.12.0"
+version = "1.12.1"
 authors = ["Shadowsocks Contributors"]
 description = "shadowsocks is a fast tunnel proxy that helps you bypass firewalls."
 repository = "https://github.com/shadowsocks/shadowsocks-rust"

bin/ssserver.rs

@@ -170,6 +170,9 @@ fn main() {
                 sc.set_plugin(plugin);
             }
 
+            // For historical reason, servers that are created from command-line have to be tcp_only.
+            sc.set_mode(Mode::TcpOnly);
+
             if matches.is_present("UDP_ONLY") {
                 sc.set_mode(Mode::UdpOnly);
             }