New system for silent require errors. Use the new function

stdnse.silent_require. The Lua require function is back in its usual spot
(_G.require).

scripts/oracle-brute.nse

@@ -37,7 +37,8 @@ categories = {"intrusive", "auth"}
 
 require 'shortport'
 require 'brute'
-require 'openssl'
+require 'stdnse'
+stdnse.silent_require 'openssl'
 require 'tns'
 
 portrule = shortport.port_or_service(1521, "oracle-tns", "tcp", "open")