try to add SRT support

[3qdev]

I try to build the alpine image with ffmpeg option --enable-libsrt.

ffmpeg version 4.0.2 do not compile, there is a bug see I think i must wait for version 4.0.3 or use the snapshot.

However in version lower then 4.x there is no option "--enable-libsrt". Is there a way to enable this only for versions greater than 3.x?

if you interested in add SRT support in this Docker Images i can share my expirience via pull request

[3qdev]

Ok, I've seen that I need to insert this into update.py

[jrottenberg]

yep check update.py , there is some logic to adjust the configure options based on versions.

Note for some reason except for centos there's some issue on ffmpeg v4 build see #119 keep an eye on it since you'll have to rebase.