Although it is classified as warning, it is nothing you have to respond to. Simply ignore those log messages. I filed an issue report to lower the severity of that: ASTERISK-29785.
Anyway, to answer your question: The related issue was ASTERISK-29625. In that issue, the causing issue is ASTERISK-26190. More details in this post … Consequently, you could re-configure Asterisk to get rid of those.
However, that does not remove the message for AES-192 either. And I do not recommend to enable AES-192 for egress (especially because your libSRTP seems not enabled with OpenSSL as crypto backend). Therefore, the easiest way is to reverse that change:
cd <in your Asterisk source tree>
wget https://gerrit.asterisk.org/changes/asterisk~16436/revisions/2/patch?zip
unzip ./c1a5759.diff.zip
patch -p1 --reverse <./c1a5759.diff
make