fixed DbIdentityManager requires mongodb user with listDatabases perm…

…inssion https://softinstigate.atlassian.net/browse/RH-231

src/main/java/org/restheart/security/impl/DbIdentityManager.java

@@ -42,6 +42,7 @@
 import org.restheart.cache.Cache;
 import org.restheart.cache.CacheFactory;
 import org.restheart.cache.LoadingCache;
+import org.restheart.db.DbsDAO;
 import org.restheart.db.MongoDBClientSingleton;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -93,28 +94,8 @@ public DbIdentityManager(Map<String, Object> arguments)
         MongoClient mongoClient = MongoDBClientSingleton
                 .getInstance().getClient();
 
-        ArrayList<String> dbNames = new ArrayList<>();
-
-        mongoClient.listDatabaseNames().into(dbNames);
-
-        if (!dbNames.contains(this.db)) {
-            throw new IllegalArgumentException(
-                    "error configuring the DbIdentityManager. "
-                    + "The specified db does not exist: " + db);
-        }
-
         MongoDatabase mongoDb = mongoClient.getDatabase(this.db);
 
-        ArrayList<String> collectionNames = new ArrayList<>();
-
-        mongoDb.listCollectionNames().into(collectionNames);
-
-        if (!collectionNames.contains(this.coll)) {
-            throw new IllegalArgumentException(
-                    "error configuring the DbIdentityManager. "
-                    + "The specified collection does not exist: " + coll);
-        }
-
         this.mongoColl = mongoDb.getCollection(coll, BsonDocument.class);
     }