switch to g711fax if to start in a mode not work since 23944

(Thanks also V.Frolov)

Final solution: switching to g711fax if to start in auto mode with faxOpal not work since 23944

>Problem #1 :we are not able to detect 'Y' that is not possible to detect fax at remote side
Already done :
24171 Removed disable of in-band DTMF detector when remote advertises it does RFC2833, as some endpoints lie about it. We rely instead on endpoints that do do RFC2833, removing the DTMF signal from the in-band path.
OK. Thank you.

>Problem #2 :FaxOpal trying to send T.38 fax, but not able to understand that "t38 not supported"
We must remove adding of t38 from one function and add to another function (from one file to another).