build,circleci: fix container digest

I used podman/buildah to build this image, and the local sha256 is not the same than
the docker hub sha256. The layers are the same, so maybe just docker hub changing the manifest

Signed-off-by: Etienne Champetier <champetier.etienne@gmail.com>

.circleci/config.yml

@@ -2,7 +2,7 @@ version: 2.0
 jobs:
   build:
     docker:
-      - image: champtar/openwrtpackagesci@sha256:82026d8d33fc9e40472c63d4512b8da2da3f6da082f2b682d55540acfb1f7fa5
+      - image: champtar/openwrtpackagesci@sha256:d46da22bc628f4b369147eebfa1b032e4066510da42a073b22acbf6b6595b77f
     environment:
       - SDK_BASE_URL: "https://downloads.lede-project.org/snapshots/targets/ar71xx/generic"
       - SDK_FILE: "openwrt-sdk-ar71xx-generic_gcc-7.3.0_musl.Linux-x86_64.tar.xz"