Updated opcua.makefile to match opcua 0.9.3 changes
There are a number of changes to opcua between 0.8.0 and 0.9.3. In particular, opcuaUaSdk.dbd
and iocshIntegrationUaSdk.cpp
have both been removed. Furthermore, the USR_CXXFLAG
-DHAS_SECURITY
has been added.