Fix an issue where SetFastLoopbackOption() throws...

Fix an issue where SetFastLoopbackOption() throws PlatformNotSupportedException on non-Windows platrorms.

StackExchange.Redis/StackExchange/Redis/SocketManager.cs

@@ -251,13 +251,19 @@ internal void SetFastLoopbackOption(Socket socket)
                 var osVersion = Environment.OSVersion.Version;
                 if (osVersion.Major > 6 || osVersion.Major == 6 && osVersion.Minor >= 2)
                 {
-#endif
                     byte[] optionInValue = BitConverter.GetBytes(1);
                     socket.IOControl(SIO_LOOPBACK_FAST_PATH, optionInValue, null);
-
-#if !CORE_CLR
                 }
             }
+#else
+            try
+            {
+                byte[] optionInValue = BitConverter.GetBytes(1);
+                socket.IOControl(SIO_LOOPBACK_FAST_PATH, optionInValue, null);
+            }
+            catch (PlatformNotSupportedException)
+            {
+            }
 #endif
         }