fix summary (#2024)

Author: mairaw

xml/System.Security.Claims/ClaimTypes.xml

@@ -1766,9 +1766,9 @@
         <ReturnType>System.String</ReturnType>
       </ReturnValue>
       <Docs>
-        <summary>The URI for a distinguished name claim of an X.509 certificate, http://schemas.xmlsoap.org/ws/2005/05/identity/claims/x500distinguishedname. The X.500 standard defines the methodology for defining distinguished names that are used by X.509 certificates.</summary>
+        <summary>The URI for an X.500 distinguished name claim, such as the subject of an X.509 Public Key Certificate or an entry identifier in a directory services Directory Information Tree.</summary>
         <remarks>To be added.</remarks>
       </Docs>
     </Member>
   </Members>
-</Type>
+</Type>