notmuch: Add "mbsync -a" to the pre-new hook

.cache/mail/.notmuch/hooks/pre-new

@@ -0,0 +1,2 @@
+#!/bin/sh
+mbsync -a

.config/cron/job.guile

@@ -21,6 +21,5 @@
 (job '(next-hour (range 0 24 3)) "updatedb-local")
 
 (job '(next-minute (range 0 60 15))
-     '(begin (system* "mbsync" "-a")
-             (system* "notmuch" "new"))
+     '(system* "notmuch" "new")         ; Email is sync'ed from a pre-new hook.
      "mail")