[FIX] base: change logger type to 'warning' on format mismatch

If applied, this commit will handle the KeyError: res_id when the user tries to
import the translation of .csv file in settings -> translations, and if .csv
file doesn't have the res_id column.

I handled the traceback by changing the logger level to warning.

sentry - 4049419481

closes odoo/odoo#120775

X-original-commit: dd0ec40c
Signed-off-by: Renilkumar Kajavadra (reka) <reka@odoo.com>
Signed-off-by: Rémy Voet <ryv@odoo.com>

odoo/addons/base/wizard/base_import_language.py

@@ -41,7 +41,7 @@ class BaseLanguageImport(models.TransientModel):
                         fileformat = splitext(base_lang_import.filename)[-1][1:].lower()
                         translation_importer.load(buf, fileformat, base_lang_import.code)
                 except Exception as e:
-                    _logger.exception('File unsuccessfully imported, due to format mismatch.')
+                    _logger.warning('File unsuccessfully imported, due to format mismatch.')
                     raise UserError(
                         _('File %r not imported due to format mismatch or a malformed file.'
                           ' (Valid formats are .csv, .po, .pot)\n\nTechnical Details:\n%s') % \