User: Remove redundant wgClockSkewFudge code

User: Remove redundant wgClockSkewFudge code

Ensuring the new value is at least as high as 1 second higher
than the current value is sufficient.

The main code paths using this are checkAndSetTouched (for user group
changes) and saveSettings(), both of which use makeUpdateConditions() which
ensures we bail out if something else already wrote to it in the mean time.
As such, there is no longer a need to make sure our time is higher than
something another server may have written, given that is no longer something
we support.

This variable was introduced in 2005 (MW 1.4) with r9403 (1d12276bcb3),
and factored out as newTouchedTimestamp() in 2007 (MW 1.8)
with r16772 (c1094ba9876).

Change-Id: I940fb0dd125286a4a348c11e2c8d197f9288a75d