Upgrade to MongoDB 2.4.3

Upgrade MongoDB to latest version 2.4.3:

"MongoDB 2.4.3 has been released.
This release fixes several issues with 2.4.2 and is a recommended upgrade for all 2.4 users.

Highlights:
Shell ignores modified object's "_id" field: https://jira.mongodb.org/browse/SERVER-9385
Race condition in log rotation: https://jira.mongodb.org/browse/SERVER-4739
Fix copydb command with auth in sharded cluster: https://jira.mongodb.org/browse/SERVER-9093

Release notes: http://docs.mongodb.org/manual/release-notes/2.4
Downloads: http://www.mongodb.org/downloads
Change Log: https://jira.mongodb.org/browse/SERVER/fixforversion/12426"