Update SseItem`1.xml

Author: gewarren

xml/System.Net.ServerSentEvents/SseItem`1.xml

@@ -38,7 +38,7 @@
     </Attribute>
   </Attributes>
   <Docs>
-    <typeparam name="T">Specifies the type of data payload in the event.</typeparam>
+    <typeparam name="T">Specifies the type of data payload in the event.Test</typeparam>
     <summary>Represents a server-sent event.</summary>
     <remarks>To be added.</remarks>
   </Docs>