Error vs warning on unsupported escapes

[F Wolff]

libgettextpo reports an error of severity PO_SEVERITY_ERROR in case of
unexpected escapes (\a, \b, \r, etc). Both msgfmt -cv and msgunfmt
doesn't seem to have a real problem with these. The code should easily
be able to write them out, and the comment in write-po.c suggests that
we only really want to warn users, not fail.

              /* We warn about any use of escape sequences beside
                 '\n' and '\t'.  */
              if (c != 'n' && c != 't')
                {
                  char *error_message =
                    xasprintf (_("\
internationalized messages should not contain the `\\%c' escape sequence"),
                               c);
                  po_xerror (PO_SEVERITY_ERROR, mp, NULL, 0, 0, false,
                             error_message);

Would it be worthwhile to change the PO_SEVERITY_ERROR to
PO_SEVERITY_WARNING instead?

Thanks
Friedel