mediastreamer: disable ffmpeg support

upstream has deprecated it [1] and considers it unmaintained [2]. only
compatible with ffmpeg4.

[1] https://gitlab.linphone.org/BC/public/mediastreamer2/-/commit/8261f82741f454d5b523f224aec3c66ee97e2fdc
[2] https://gitlab.linphone.org/BC/public/mediastreamer2/-/commit/a455e96189eda038f4de51a8a0b874215ca86226

Author: classabbyamp

srcpkgs/mediastreamer/template

@@ -1,12 +1,12 @@
 # Template file for 'mediastreamer'
 pkgname=mediastreamer
 version=5.3.106
-revision=1
+revision=2
 build_style=cmake
 configure_args="-DENABLE_STRICT=0 -DENABLE_UNIT_TESTS=0 -DBUILD_SHARED_LIBS=TRUE
- -DENABLE_QT_GL=TRUE"
+ -DENABLE_QT_GL=TRUE -DENABLE_FFMPEG=0"
 hostmakedepends="python3 qt5-qmake qt5-host-tools"
-makedepends="bzrtp-devel ffmpeg-devel glew-devel libXv-devel libsrtp-devel
+makedepends="bzrtp-devel glew-devel libXv-devel libsrtp-devel
  libupnp-devel libvpx-devel mbedtls-devel opus-devel ortp-devel pulseaudio-devel
  libtheora-devel speex-devel v4l-utils-devel bcg729-devel bcmatroska2-devel libgsm-devel
  zxing-cpp-devel libaom-devel qt5-devel qt5-declarative-devel"