Highlighting with GeoPointInBBoxQuery can result in Exception

Highlighter and GeoPointInBBoxQuery don't play well together. I wrote a test here that throws an exception which I think it should not:

https://github.com/brwe/lucene-solr/commit/311f5527ffb6f3ef50e3f74b54456aa7b29d8898

The problem seems to be that GeoPointInBBoxQuery calls rewrite with a reader that contains a text field (which we want to highlight) and therefore has the wrong encoding.

This is from an elasticsearch issue: https://github.com/elastic/elasticsearch/issues/17537