Add null check to GetAttributeType
Add null check to GetAttributeType

Fix #30

AgileJoshua/ConfuserEx,HalidCisse/ConfuserEx,yuligang1234/ConfuserEx,engdata/ConfuserEx,jbeshir/ConfuserEx,fretelweb/ConfuserEx,MetSystem/ConfuserEx,mirbegtlax/ConfuserEx,timnboys/ConfuserEx,JPVenson/ConfuserEx,JPVenson/ConfuserEx,manojdjoshi/ConfuserEx,yeaicc/ConfuserEx,apexrichard/ConfuserEx,Desolath/Confuserex,farmaair/ConfuserEx,arpitpanwar/ConfuserEx,mirbegtlax/ConfuserEx,KKKas/ConfuserEx,HalidCisse/ConfuserEx,Immortal-/ConfuserEx,Desolath/ConfuserEx3,yuligang1234/ConfuserEx,modulexcite/ConfuserEx