Fixing some bugs

Author: DiegoGalante

src/Entities/WorkItem.cs

@@ -95,7 +95,7 @@ public void AddTimeByState(TimeByState timeByState)
 
         public void AddTimesByState(IEnumerable<TimeByState> timesByState)
         {
-            if (timesByState is not null && !timesByState.Any())
+            if (timesByState is null && !timesByState.Any())
                 return;
 
             foreach (var timeByState in timesByState)

src/Extensions/HelperExtenions.cs

@@ -25,7 +25,7 @@ public static string ExtractEmail(this string user)
             if (!user.Contains(" <") && !user.TrimEnd().Contains(">"))
                 return user;
 
-            return user.Split("<").LastOrDefault().Split(">").FirstOrDefault();
+            return user.Split("<").LastOrDefault()?.Split(">")?.FirstOrDefault();
         }
 
         public static string ToTextTime(this TimeSpan timeSpan)