Update SslProtocols property value (#11247)

Author: gewarren

xml/System.Net.Http/HttpClientHandler.xml

@@ -1234,8 +1234,8 @@ handler.ServerCertificateCustomValidationCallback = HttpClientHandler.DangerousA
         <ReturnType>System.Security.Authentication.SslProtocols</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>Gets or sets the TLS/SSL protocol used by the <see cref="T:System.Net.Http.HttpClient" /> objects managed by the HttpClientHandler object.</summary>
-        <value>One of the values defined in the <see cref="T:System.Security.Authentication.SslProtocols" /> enumeration.</value>
+        <summary>Gets or sets the TLS/SSL protocols used by the <see cref="T:System.Net.Http.HttpClient" /> objects managed by the HttpClientHandler object.</summary>
+        <value>A bitwise combination of the enumeration values that specify the TLS/SSL protocols.</value>
         <remarks>To be added.</remarks>
         <exception cref="T:System.PlatformNotSupportedException">.NET Framework 4.7.1 only: This property is not implemented.</exception>
       </Docs>