fix error cases when internationalizable is not defined on rdef

1              return choosed
2          # All other case, generate a default string
3          attrlength = get_max_length(self.eschema, attrname)
4          num_len = numlen(index)
5          if num_len >= attrlength:
6 -            ascii = self.eschema.rdef(attrname).internationalizable
7 +            ascii = getattr(self.eschema.rdef(attrname), 'internationalizable', False)
8              return ('&'+decompose_b26(index, ascii))[:attrlength]
9          # always use plain text when no format is specified
10          attrprefix = attrname[:max(attrlength-num_len-1, 0)]
11          if format == 'text/html':
12              value = u'<span>�%s<b>%d</b></span>' % (attrprefix, index)