Exclude SslProtocols tests when targeting CORE_CLR

MigratedBookSleeveTestSuite/Config.cs

@@ -187,7 +187,7 @@ public void CreateDisconnectedNonsenseConnection_DNS()
                 Console.WriteLine(log);
             }
         }
-
+#if !CORE_CLR
         [Test]
         public void SslProtocols_SingleValue()
         {
@@ -223,6 +223,7 @@ public void SslProtocols_InvalidValue()
             var log = new StringWriter();
             Assert.Throws<ArgumentOutOfRangeException>(() => ConfigurationOptions.Parse("myhost,sslProtocols=InvalidSslProtocol"));            
         }
+#endif //#if !CORE_CLR
 
         [Test]
         public void ConfigurationOptionsDefaultForAzure()