Bug 832998:  Fix a backwards OMTA-throttling-enabled check, to fix performance regression on the non-OMTA-throttling case.  r=nrc  approval-mozilla-beta=lsblakk

--HG--
extra : transplant_source : %21%03%DD1%01%CEK%60%D7%E4%F8%7D%C16Q%B7%3E%D3%93%C2