filtertopic.lua

local function topic_event(args)
  if args[3] == "#cc.ru-server1" then
    return hexchat.EAT_HEXCHAT
  end
end

hexchat.hook_print("Topic Change", topic_event)

hexchat.register("filtertopic", "1.0.0", "Ignores topic changes in #cc.ru-server1")

filtertopic.py

import hexchat

__module_name__        = "filtertopic"
__module_version__     = "1.0.0"
__module_description__ = "Ignores topic changes in #cc.ru-server1"

def topic_event(word, word_eol, userdata):
    if word_eol[2] == "#cc.ru-server1":
        return hexchat.EAT_HEXCHAT

hexchat.hook_print("Topic Change", topic_event)