Fix: wrong version in legacy meek protocol check

Protocol version 1 can handle > 64K response bodies.
Check should be for version < 1. See:
https://bitbucket.org/psiphon/psiphon-circumvention-system/src/5c4b43df950b24441e5b6f4af187144862fa9f92/go/meek-server/meek-server.go?at=default&fileviewer=file-view-default#meek-server.go-193

psiphon/server/meek.go

@@ -709,8 +709,8 @@ func (conn *meekConn) pumpWrites(writer io.Writer) error {
 				return err
 			}
 
-			if conn.protocolVersion < MEEK_PROTOCOL_VERSION_2 {
-				// Protocol v1 clients expect at most
+			if conn.protocolVersion < MEEK_PROTOCOL_VERSION_1 {
+				// Pre-protocol version 1 clients expect at most
 				// MEEK_MAX_PAYLOAD_LENGTH response bodies
 				return nil
 			}