Reduce depth of exception cause to pass tests

The changes to expose GeoShapeQueryable.toQuantizeLuceneGeometry to
external use also caused exception causes to be one level deeper.
This fix just brings the underlying message up one level to get
tests to pass.
While we could have also changed tests to assert on causes a level
deeper, this fix seems more backwards compatible, just in case anyone
else is relying on causes.

server/src/main/java/org/elasticsearch/index/mapper/GeoShapeQueryable.java

@@ -48,7 +48,7 @@ default Query geoShapeQuery(SearchExecutionContext context, String fieldName, Sh
         try {
             luceneGeometries = toQuantizeLuceneGeometry(shape, relation);
         } catch (IllegalArgumentException e) {
-            throw new QueryShardException(context, "Exception creating query on Field [" + fieldName + "]", e);
+            throw new QueryShardException(context, "Exception creating query on Field [" + fieldName + "] " + e.getMessage(), e);
         }
         if (luceneGeometries.length == 0) {
             return new MatchNoDocsQuery();