Corrected wrong value of ClientCertificateOptions (#10608)

* Corrected wrong value of ClientCertificateOptions

* Apply review suggestion

Co-authored-by: Genevieve Warren <[email protected]>

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Co-authored-by: Miha Zupan <[email protected]>
Co-authored-by: Genevieve Warren <[email protected]>

Author: 3 people

xml/System.Net.Http/HttpClientHandler.xml

@@ -281,7 +281,7 @@ After NuGet package v4.3.2, the default value of <xref:System.Net.DecompressionM
       </ReturnValue>
       <Docs>
         <summary>Gets or sets a value that indicates if the certificate is automatically picked from the certificate store or if the caller is allowed to pass in a specific client certificate.</summary>
-        <value>The collection of security certificates associated with this handler.</value>
+        <value>One of the enumeration values. The default value is <see cref="F:System.Net.Http.ClientCertificateOption.Manual" />.</value>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>