correct prop

Author: tilen1976

klass-api/src/main/resources/application-remote-open-search.properties

@@ -1,4 +1,4 @@
 klass.env.search.elasticsearch.index=klass
-opensearch.user=${OPEN_SEARCH_USERNAME}
+opensearch.username=${OPEN_SEARCH_USERNAME}
 opensearch.url=${OPEN_SEARCH_URI}
 opensearch.password=${OPEN_SEARCH_PASSWORD}