docs: no default value for mod_proxy upgrade= parameter. [skip ci]

Merges r1907045 from https://svn.apache.org/repos/asf/httpd/httpd/trunk.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1907047 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/docs/manual/mod/mod_proxy.xml b/docs/manual/mod/mod_proxy.xml
index dbd85914a601ad81d2e9cec096b249e76ab3fd92..9cd215d2b49a2d1364222c48f002c9280ae81484 100644 (file)
--- a/docs/manual/mod/mod_proxy.xml
+++ b/docs/manual/mod/mod_proxy.xml
@@ -1242,7 +1242,7 @@ ProxyPass "/example" "http://backend.example.com" max=20 ttl=120 retry=300
         Available in Apache HTTP Server 2.4.42 and later.
     </td></tr>
     <tr><td><a id="upgrade" name="upgrade">upgrade</a></td>
-        <td>WebSocket</td>
+        <td>-</td>
         <td><p>Protocol accepted by <module>mod_proxy_http</module> or
         <module>mod_proxy_wstunnel</module> for the HTTP Upgrade mechanism
         upon negotiation by the HTTP client/browser (per