Fixed out-of-date documentation for CodedInputStream.ReadEnum. (#1581)

diff --git a/csharp/src/Google.Protobuf/CodedInputStream.cs b/csharp/src/Google.Protobuf/CodedInputStream.cs
index ce6856d..072e2e1 100644
--- a/csharp/src/Google.Protobuf/CodedInputStream.cs
+++ b/csharp/src/Google.Protobuf/CodedInputStream.cs
@@ -612,9 +612,7 @@
         }

 

         /// <summary>

-        /// Reads an enum field value from the stream. If the enum is valid for type T,

-        /// then the ref value is set and it returns true.  Otherwise the unknown output

-        /// value is set and this method returns false.

+        /// Reads an enum field value from the stream.

         /// </summary>   

         public int ReadEnum()

         {