Fixed error in Troe kinetics writing to Chemkin file.
Fixed error in Troe kinetics writing to Chemkin file.

The bug involved incorrect checking for the case when the T2 Troe
parameter is not used.

pierrelb/RMG-Py,faribas/RMG-Py,KEHANG/RMG-Py,comocheng/RMG-Py,comocheng/RMG-Py,nyee/RMG-Py,enochd/RMG-Py,nickvandewiele/RMG-Py,chatelak/RMG-Py,KEHANG/RMG-Py,nyee/RMG-Py,enochd/RMG-Py,faribas/RMG-Py,pierrelb/RMG-Py,nickvandewiele/RMG-Py,chatelak/RMG-Py