Update HttpWebRequest.xml (dotnet#9137)

Remove outdated and unsupported value of -1 from the documentation.

Co-authored-by: Anupam Srivastava <[email protected]>

Author: anupamsr

xml/System.Net/HttpWebRequest.xml

@@ -2495,13 +2495,13 @@ Both <xref:System.Net.HttpWebRequest> constructors are obsolete and should not b
           <format type="text/markdown"><![CDATA[
 
 ## Remarks
- The length of the response header received the response status line and any extra control characters that are received as part of HTTP protocol. A value of -1 means no limit is imposed on the response headers received; a value of 0 means that all requests fail.
+ The length of the response header received the response status line and any extra control characters that are received as part of HTTP protocol. A value of 0 means that all requests fail.
 
  This value can also be changed in the configuration file. The impact of this property can be overridden by setting the <xref:System.Net.HttpWebRequest.MaximumResponseHeadersLength%2A> property on an instance of the <xref:System.Net.HttpWebRequest> class.
 
  ]]></format>
         </remarks>
-        <exception cref="T:System.ArgumentOutOfRangeException">The value is not equal to -1 and is less than zero.</exception>
+        <exception cref="T:System.ArgumentOutOfRangeException">The value is less than zero.</exception>
       </Docs>
     </Member>
     <MemberGroup MemberName="EndGetRequestStream">
@@ -3701,7 +3701,7 @@ The GetHashCode method returns a hash code of the web request. This value can be
           <format type="text/markdown"><![CDATA[
 
 ## Remarks
- The length of the response header includes the response status line and any extra control characters that are received as part of HTTP protocol. A value of -1 means no limit is imposed on the response headers; a value of 0 means that all requests fail.
+ The length of the response header includes the response status line and any extra control characters that are received as part of HTTP protocol. A value of 0 means that all requests fail.
 
  If the <xref:System.Net.HttpWebRequest.MaximumResponseHeadersLength%2A> property is not explicitly set, it defaults to the value of the <xref:System.Net.HttpWebRequest.DefaultMaximumResponseHeadersLength%2A> property.
 
@@ -3719,7 +3719,7 @@ The GetHashCode method returns a hash code of the web request. This value can be
  ]]></format>
         </remarks>
         <exception cref="T:System.InvalidOperationException">The property is set after the request has already been submitted.</exception>
-        <exception cref="T:System.ArgumentOutOfRangeException">The value is less than 0 and is not equal to -1.</exception>
+        <exception cref="T:System.ArgumentOutOfRangeException">The value is less than 0.</exception>
       </Docs>
     </Member>
     <Member MemberName="MediaType">