store_info_insert_folder_info: Use g_hash_table_replace() to avoid use-after-free

The previously used g_hash_table_insert() replaces only value for keys
which are already included in the hash table, but as the key is owned
by the value and freed together with the value, then here should
be used g_hash_table_replace(), which replaces both key and value,
thus avoids the use-after-free on the hash table's key.