film_grain: include config.h before other headers

Fixes warnings about redefinition of _WIN32_WINNT on Windows targets
12 jobs for master in 6 minutes and 22 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Build
passed build-debian #235501
debian amd64

00:00:32

passed build-debian-aarch64 #235505
aarch64 debian

00:01:48

passed build-debian-aarch64-clang-5 #235506
aarch64 clang5 debian

00:01:22

passed build-debian-static #235502
debian amd64

00:00:32

passed build-debian-werror #235508
aarch64 debian

00:00:33

passed build-macos #235507
macos

00:00:25

passed build-win32 #235503
win32

00:00:29

passed build-win64 #235504
win64

00:00:34

 
  Test
passed test-debian #235509
debian amd64

00:00:44

passed test-debian-asan #235510
debian amd64

00:02:28

passed test-debian-msan #235511
debian aarch64

00:01:26

passed test-debian-ubsan #235512
debian amd64

00:01:00