fix hidden buffer tabs not showing in tabufline with less space

credits to @ii14 for helping me fix this issue

lua/core/utils.lua

@@ -137,8 +137,7 @@ end
 M.load_override = function(default_table, plugin_name)
    local user_table = M.load_config().plugins.override[plugin_name] or {}
    user_table = type(user_table) == "table" and user_table or user_table()
-
-   return user_table and merge_tb("force", default_table, user_table)
+   return merge_tb("force", default_table, user_table)
 end
 
 M.packer_sync = function(...)