Bug 853908 email: point where to find codepages parts not in protocol

activesync/codepages is split across two build layers, as part of the change for [852710](https://bugzilla.mozilla.org/show_bug.cgi?id=852710). However, for account setup where there is not an autoconfig match, activesync/protocol is loaded by itself in accountcommon.js. Since the layer that has activesync/protocol does not have all of activesync/codepagse in it, the location of the other parts of activesync/codepages needs to be configured. This patch addresses that issue.

Tested on a non-autoconfig account, and code scanned for any other activesync side loading. This was the only one that was missed as part of 852710.