Typo in shell code 'contiuue' -> 'continue'

I found a typo in the GRIB library build scripts that was causing the build process described in http://www.openwfm.org/wiki/How_to_run_WRF-Fire to fail out of the box.  This fixed it.

I am working with Dr. Jeff Pierce at Colorado State, where he plans to run this model on our Linux cluster.