fixing strava import failure

rowers/utils.py

@@ -377,7 +377,12 @@ def totaltime_sec_to_string(totaltime):
         if not message:
             message = 'Warning: there is something wrong with the workout duration'
 
-    duration = "%s:%s:%s.%s" % (hours, minutes, seconds, tenths)
+    duration = "{hours:02d}:{minutes:02d}:{seconds:02d}.{tenths}".format(
+        hours=hours,
+        minutes=minutes,
+        seconds=seconds,
+        tenths=tenths
+        )
 
     return duration