Bug 1251734 - Increase TC Linux64 jetpack timeout. DONTBUILD. r=jmaher

MozReview-Commit-ID: Hlw73xHpoU4

testing/taskcluster/tasks/tests/fx_linux64_mochitest_jetpack.yml

@@ -7,6 +7,7 @@ task:
     name: '[TC] Linux64 mochitest-jetpack'
     description: Mochitest jetpack run
   payload:
+    maxRunTime: 5400
     capabilities:
       devices:
         loopbackVideo: true