remove redundant option - enableCallStats

JitsiConference.js

             callStatsID: config.callStatsID,
             callStatsSecret: config.callStatsSecret,
             callStatsApplicationLogsDisabled: config.callStatsApplicationLogsDisabled,
-            enableCallStats: true,
             roomName: this.options.name,
             applicationName: config.applicationName,
             configParams: config.callStatsConfigParams

modules/statistics/statistics.js

     this.options = options || {};
 
     this.callStatsIntegrationEnabled
-        = this.options.callStatsID && this.options.callStatsSecret && this.options.enableCallStats
+        = this.options.callStatsID && this.options.callStatsSecret
 
             // Even though AppID and AppSecret may be specified, the integration
             // of callstats.io may be disabled because of globally-disallowed