修复振铃时间计算错误

src/Hotline.Application/Jobs/XingTangCallsSyncJob.cs

@@ -99,11 +99,11 @@ namespace Hotline.Application.Jobs
                         {
                             if (call.EndRingTime != null)
                             {
-                                call.RingDuration = call.BeginRingTime.Value.GetDifferenceSeconds(call.EndRingTime.Value);
+                                call.RingDuration = call.EndRingTime.Value.GetDifferenceSeconds(call.BeginRingTime.Value);
                             }
                             else
                             {
-                                call.RingDuration = call.BeginRingTime.Value.GetDifferenceSeconds(call.EndTime);
+                                call.RingDuration = call.EndTime.GetDifferenceSeconds(call.BeginRingTime.Value);
                             }
                         }
                     }