Elastic Search backend instance breaks Search API Server form when more than 1 type of search backend is active
I am getting an issue where you have an elasticsearch index and a second type of search like solr.
When you acess the Edit Server form for the other type of search index (eg Solr) search api, the webpage crashes with the following error:
Drupal\search_api\SearchApiException: Cannot load the Elasticsearch cluster for your index. in Drupal\elasticsearch_connector\Plugin\search_api\backend\SearchApiElasticsearchBackend->__construct() (line 205 of modules/contrib/elasticsearch_connector/src/Plugin/search_api/backend/SearchApiElasticsearchBackend.php).
`SearchApiElasticsearchBackend` does not check to see if it is the active search backend instance for the page before throwing error.
1. Create a solr search index
2. Create an elastic search index
3. Attempt to edit the solr search server
4. Website crashes
Active
7.0
Elasticsearch Connector
Added patch that checks to see if it is the active backend before throwing exception.
Updated for change in settings structure and updated issue priority to major as it blocks viewing non-elasticsearch server pages.
Improved the patch, early exit from the `SearchApiElasticsearchBackend::_construct` if it is not active backend.