the server/replset/mongos options are deprecated, all their options are supported at the top level of the options object [poolSize,ssl,sslValidate,sslCA,sslCert,ciphers,ecdhCurve,sslKey,sslPass,sslCRL,autoReconnect,noDelay,keepAlive,connectTimeoutMS,family,socketTimeoutMS,reconnectTries,reconnectInterval,ha,haInterval,replicaSet,secondaryAcceptableLatencyMS,acceptableLatencyMS,connectWithNoPrimary,authSource,w,wtimeout,j,forceServerObjectId,serializeFunctions,ignoreUndefined,raw,bufferMaxEntries,readPreference,pkFactory,promiseLibrary,readConcern,maxStalenessSeconds,loggerLevel,logger,promoteValues,promoteBuffers,promoteLongs,domainsEnabled,keepAliveInitialDelay,checkServerIdentity,validateOptions,appname,auth]
Fixes this warning on startup: