Bug 874348 - [Buri][Email]Failed to send and receive mail with 163 exchange account. r=asuth

take jimporter's jsas changes from:
https://github.com/mozilla-b2g/jsas/pull/12

which landed in jsas/worker-thread:
https://github.com/mozilla-b2g/jsas/commit/b953c81b8dad7be4a4cc7a228e69fcef3df5a107