avcfg: Fix AVOptionRanges leak

It must be freed with av_opt_freep_ranges as documented.
8 jobs for fix-leak in 15 minutes and 42 seconds
Status Job ID Name Coverage
  Preparation
passed #79163
gst indent

00:00:20

passed #79162
manifest

00:00:38

 
  Build
passed #79164
build fedora x86_64

00:03:18

 
  Test
passed #79165
check fedora

00:03:39

 
  Full Builds
passed #79166
build android arm64 api28

00:04:34

passed #79168
build cerbero cross win32

00:07:51

passed #79169
build cerbero cross win64

00:05:40

passed #79167
build cerbero fedora x86_64

00:08:05