[util] adjust Firefox/Chrome UA versions

modify 'ordinal' offsets to get the correct version numbers

gallery_dl/util.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2017-2025 Mike Fährmann
+# Copyright 2017-2026 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -697,8 +697,9 @@ class Flags():
 #  _ff_ver = (_ord_today - 735506) // 28
 #  _ch_ver = (_ord_today - 735562) // 28
 
-_ff_ver = (dt.date.today().toordinal() - 735506) // 28
-#  _ch_ver = _ff_ver - 2
+_ord_today = dt.date.today().toordinal()
+_ff_ver = (_ord_today - 735_513) // 28  # 147 on 2026-01-13
+_ch_ver = (_ord_today - 735_599) // 28  # 143 on 2025-12-18
 
 re = text.re
 re_compile = text.re_compile
@@ -720,7 +721,7 @@ USERAGENT_FIREFOX = (f"Mozilla/5.0 (Windows NT 10.0; Win64; x64; "
                      f"rv:{_ff_ver}.0) Gecko/20100101 Firefox/{_ff_ver}.0")
 USERAGENT_CHROME = ("Mozilla/5.0 (Windows NT 10.0; Win64; x64) "
                     "AppleWebKit/537.36 (KHTML, like Gecko) "
-                    f"Chrome/{_ff_ver - 2}.0.0.0 Safari/537.36")
+                    f"Chrome/{_ch_ver}.0.0.0 Safari/537.36")
 
 GLOBALS = {
     "contains" : contains,

gallery_dl/version.py

@@ -6,5 +6,5 @@
 # it under the terms of the GNU General Public License version 2 as
 # published by the Free Software Foundation.
 
-__version__ = "1.31.2"
+__version__ = "1.31.3-dev"
 __variant__ = None