adding tracing in calibration upload to fix issue wiht one user

xdrip/Managers/NightScout/NightScoutUploadManager.swift

@@ -264,6 +264,9 @@ public class NightScoutUploadManager:NSObject {
             // 2 records are uploaded to nightscout for each calibration: a cal record and a mbg record
             let calibrationsDictionaryRepresentation = calibrationsToUpload.map({$0.dictionaryRepresentationForCalRecordNightScoutUpload}) + calibrationsToUpload.map({$0.dictionaryRepresentationForMbgRecordNightScoutUpload})
 
+            let traceValue = calibrationsDictionaryRepresentation.description
+            trace("tracevalue = %{public}@", log: oslog, category: ConstantsLog.categoryNightScoutUploadManager, type: .info, traceValue)
+
             uploadData(dataToUpload: calibrationsDictionaryRepresentation, traceString: "uploadCalibrationsToNightScout", siteURL: siteURL, path: nightScoutEntriesPath, apiKey: apiKey, completionHandler: {
 
                 // change timeStampLatestNightScoutUploadedCalibration
@@ -296,6 +299,16 @@ public class NightScoutUploadManager:NSObject {
             // transform dataToUpload to json
             let dateToUploadAsJSON = try JSONSerialization.data(withJSONObject: dataToUpload, options: [])
 
+            if let dateToUploadAsJSONAsString = String(bytes: dateToUploadAsJSON, encoding: .utf8) {
+
+                trace("dateToUploadAsJSON =  %{public}@", log: oslog, category: ConstantsLog.categoryNightScoutUploadManager, type: .info, dateToUploadAsJSONAsString)
+
+
+
+            } else {
+                trace("could not create dateToUploadAsJSON", log: oslog, category: ConstantsLog.categoryNightScoutUploadManager, type: .info)
+            }
+
             if let url = URL(string: siteURL) {
 
                 // create upload url