Impacted versions:
Master branch, should by 12.0

Steps to reproduce:
Install a third party addon with localization po file in i18n folder, even loading translation manually, the translation won't work, The console reports error: Translation .... not found in reference pot, skipping.
Reverse the change of  "odoo/tools/translate.py" in this commit, the issue was gone.

Expected behavior:
The po translation works as before.



odoo/addons/test_translation_import/tests/test_term_count.py
"""
        Make sure no update do not overwrite translations
        """
        menu = self.env.ref('test_translation_import.menu_test_translation_import')
        menu.name = "New Name"
        
        odoo.tools.trans_load(self.cr, 'test_translation_import/i18n/fr.po', 'fr_FR', module_name='test_translation_import', verbose=False)
        menu.with_context(lang='fr_FR').name = "Nouveau nom"
        
        odoo.tools.trans_load(self.cr, 'test_translation_import/i18n/fr.po', 'fr_FR', module_name='test_translation_import', verbose=False, context={'overwrite': True})
        
        menu.clear_caches()
        self.assertEqual(menu.name, "New Name")
        self.assertEqual(menu.with_context(lang='fr_FR').name, "Nouveau nom")
    def test_no_duplicate(self):
        """
        Just make sure we do not create duplicated translation with 'code' type
        """
        odoo.tools.trans_load(self.cr, 'test_translation_import/i18n/fr.po', 'fr_FR', module_name='test_translation_import', verbose=False)
        ids = self.env['ir.translation'].search(
            [('src', '=', 'Test translation with two code lines')])
        self.assertEqual(len(ids), 1)
        ids = self.env['ir.translation'].search(
            [('src', '=', 'Test translation with a code type but different line number in pot')])
        self.assertEqual(len(ids), 1)
        ids = self.env['ir.translation'].search(
            [('src', '=', 'Test translation with two code type and model')])
        self.assertEqual(len(ids), 2)
        self.assertEqual(len(ids.filtered(lambda t: t.type == 'code')), 1)
    def test_export_empty_string(self):