core: Fix ConfigValues.VdsLoadBalancingeIntervalInMinutes name

Renames ConfigValues attribute VdsLoadBalancingeIntervalInMinutes
to VdsLoadBalancingIntervalInMinutes.

Change-Id: I11344bc6b86502460250d2c5c7648d355addb8b4
Bug-Url: https://bugzilla.redhat.com/1112036
Signed-off-by: Martin Perina <mperina@redhat.com>