Fix Stream.CanSeek remarks (#4998)

Author: Sergio0694

xml/System.IO/Stream.xml

@@ -442,7 +442,7 @@
           <format type="text/markdown"><![CDATA[  
   
 ## Remarks  
- If a class derived from <xref:System.IO.Stream> does not support seeking, calls to <xref:System.IO.Stream.Length%2A>, <xref:System.IO.Stream.SetLength%2A>, <xref:System.IO.Stream.Position%2A>, and <xref:System.IO.Stream.Seek%2A> throw a <xref:System.NotSupportedException>.  
+ If a class derived from <xref:System.IO.Stream> does not support seeking, calls to <xref:System.IO.Stream.Length%2A>, <xref:System.IO.Stream.SetLength%2A>, <xref:System.IO.Stream.Position%2A>, and <xref:System.IO.Stream.Seek%2A> may throw a <xref:System.NotSupportedException>.  
   
  ]]></format>
         </remarks>