autogen.sh: update to match updated common submodule

Unbreaks the autotools build and fixes #15.
6 jobs for master in 32 minutes and 41 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Preparation
passed #70969
gst indent

00:00:17

passed #70968
manifest

00:00:26

 
  Build
passed #70970
build fedora x86_64

00:04:43

 
  Test
passed #70971
check fedora

00:16:43

 
  Full Builds
passed #70972
build android arm64 api28

00:06:20

passed #70973
build cerbero fedora x86_64

00:10:48