rarinfo tool throw exception if no ResourceAdapter

Report by lgao:
If generated code hasn't ResourceAdapter, rarinfo tool will throw exception

java.lang.NullPointerException
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:264)
    at org.jboss.jca.as.rarinfo.Main.getIntrospectedProperties(Main.java:1001)
    at org.jboss.jca.as.rarinfo.Main.main(Main.java:347)
  Unable to resolve introspected config-property's