travis: Fix condition when USE_GASNET unset.
travis: Fix condition when USE_GASNET unset.

sdalton1/legion,chuckatkins/legion,StanfordLegion/legion,chuckatkins/legion,StanfordLegion/legion,StanfordLegion/legion,StanfordLegion/legion,sdalton1/legion,chuckatkins/legion,sdalton1/legion,StanfordLegion/legion,chuckatkins/legion,StanfordLegion/legion,chuckatkins/legion,sdalton1/legion,sdalton1/legion,StanfordLegion/legion,chuckatkins/legion,sdalton1/legion,StanfordLegion/legion,chuckatkins/legion