Bug 19575: (RM follow-up) Fix mapping typo

Found with QA tools, simple fix

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>

admin/searchengine/elasticsearch/mappings.yaml

@@ -264,6 +264,8 @@ authorities:
         marc_field: 155a
         marc_type: normarc
         sort: ~
+        suggestible: ''
+      - facet: ''
         marc_field: 200a
         marc_type: unimarc
         sort: 1