Bug 1583742 - Upgrade docker image for clang based analysis. r=bastien,sylvestre

Differential Revision: https://phabricator.services.mozilla.com/D47048

--HG--
extra : moz-landing-system : lando

taskcluster/ci/source-test/clang.yml

@@ -15,7 +15,7 @@ job-defaults:
         by-platform:
             linux64.*: t-linux-xlarge
     worker:
-        docker-image: {in-tree: debian7-amd64-build}
+        docker-image: {in-tree: static-analysis-build}
         max-run-time: 5400
     treeherder:
         kind: other