vendor: Update everything

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/4620

vendor/golang.org/x/net/ipv4/payload.go

@@ -4,7 +4,11 @@
 
 package ipv4
 
-import "net"
+import (
+	"net"
+
+	"golang.org/x/net/internal/socket"
+)
 
 // BUG(mikio): On Windows, the ControlMessage for ReadFrom and WriteTo
 // methods of PacketConn is not implemented.
@@ -12,7 +16,8 @@ import "net"
 // A payloadHandler represents the IPv4 datagram payload handler.
 type payloadHandler struct {
 	net.PacketConn
+	*socket.Conn
 	rawOpt
 }
 
-func (c *payloadHandler) ok() bool { return c != nil && c.PacketConn != nil }
+func (c *payloadHandler) ok() bool { return c != nil && c.PacketConn != nil && c.Conn != nil }