buildroot

pangomm: roll back to version 2.38.1

2.39.1 (and all odd-numbered versions for y in x.y.z) are development
releases not intended for general usage, so roll back to the latest
stable version.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>