Fixes bug #1184941
openstack.common.log gives a mechanism to configure logging and, by
default, we will set up a handler on root logger. Using pecan to also
configure a handler on the 'ironic' logger means every log message gets
logged to console twice.
It seems that the pecan logging configuration stuff is redundant with
our existing logging configuration infrastructure.
Change-Id: Iec0630b0e842e3b6a90021bf552d9b857c5a0552