Lower default hl.fragAlignRatio

The hl.fragAlignRatio (for Unified Highlighter) has a large impact on performance. The default of 0.5 tries to place the highlighted words in the middle of the fragment. Lowering to somewhere between 0.20 and 0.33 can help a lot – see SOLR-15246 and previously in https://lists.apache.org/thread.html/r2e44d290eac9edfa61ed9eced0d9f01a7bd1cbdf910344b2aa2368b8%40%3Csolr-user.lucene.apache.org%3E

Lowering to 0.33 (to thus first third) is a better balance.