TUN-4701: Split Proxy into ProxyHTTP and ProxyTCP

http.Request now is only used by ProxyHTTP and not required if the
proxying is TCP. The dest conversion is handled by the transport layer.

ingress/origin_proxy.go

@@ -1,7 +1,6 @@
 package ingress
 
 import (
-	"fmt"
 	"net"
 	"net/http"
 
@@ -9,7 +8,6 @@ import (
 )
 
 var (
-	switchingProtocolText        = fmt.Sprintf("%d %s", http.StatusSwitchingProtocols, http.StatusText(http.StatusSwitchingProtocols))
 	errUnsupportedConnectionType = errors.New("internal error: unsupported connection type")
 )