Indicator placement problem (perhaps null)

With pygments-main 6aef43100143 and regexlint 4a7a1355, I see

```
Module pygments.lexers.rdf
E101:SparqlLexer:root:pat#5: Null characters not allowed (python docs)
  ...00-\ufdcf\ufdf0-\ufffd]|[^\x00-\uffff]|[\ud800-\udbff][\udc00-\udfff])|_...
                                         ^^^^ here
```
