smashrun: fix lap calculation

When converting a smashrun run into an Activity, i made some mistakes
calculating the start time of a lap (every lap had the same start time),
resulting in duplicate waypoints across laps.

Among other things, the resulted in some weird graphs in activities
synced from Smashrun to Garmin Connect.

tapiriik/services/Smashrun/smashrun.py

@@ -126,11 +126,12 @@ def DownloadActivity(self, serviceRecord, activity):
             # no laps, just make one big lap
             activity.Laps = [Lap(startTime=activity.StartTime, endTime=activity.EndTime, stats=activity.Stats)]
 
-        prevEndTime = activity.StartTime
+        startTime = activity.StartTime
         for lapRecord in act['laps']:
-            lap = Lap(startTime=prevEndTime,
-                      endTime=prevEndTime + timedelta(seconds=lapRecord['endDuration']))
+            endTime = activity.StartTime + timedelta(seconds=lapRecord['endDuration'])
+            lap = Lap(startTime=startTime, endTime=endTime)
             activity.Laps.append(lap)
+            startTime = endTime + timedelta(seconds=1)
 
         for value in zip(*act['recordingValues']):
             record = dict(zip(recordingKeys, value))
@@ -156,6 +157,7 @@ def DownloadActivity(self, serviceRecord, activity):
             for lap in activity.Laps:
                 if lap.StartTime <= wp.Timestamp <= lap.EndTime:
                     lap.Waypoints.append(wp)
+                    break
 
         return activity