Update index.mdx (#276)

Does not exist sip_renegotiate_codec_on_reinvite

Author: Len-PGH

docs/FreeSWITCH-Explained/Configuration/Sofia-SIP-Stack/index.mdx

@@ -735,10 +735,6 @@ Changing the SIP Contact user FreeSWITCH normally uses mod\_sofia@[ip:port](http
 {sip_contact_user=foo}sofia/my_profile/[email protected];transport=tcp
 ```
 
-##### sip_renegotiate_codec_on_reinvite
-
-true|false
-
 ##### sip_recovery_break_rfc
 
 true|false