Fix an issue where SetFastLoopbackOption throws throws a SocketException...

Fix an issue where SetFastLoopbackOption throws throws a SocketException instead of a PlatformNotSupportedException on Win 2008 R2.

StackExchange.Redis/StackExchange/Redis/SocketManager.cs

@@ -264,6 +264,9 @@ internal void SetFastLoopbackOption(Socket socket)
             catch (PlatformNotSupportedException)
             {
             }
+            catch (SocketException)
+            {
+            }
 #endif
         }