fix normalisation so we don't coerce to 0

don't coerce nil to 0

Author: David Maloney

lib/msf/core/opt_int.rb

@@ -15,8 +15,10 @@ def type
   def normalize(value)
     if value.to_s.match(/^0x[a-fA-F\d]+$/)
       value.to_i(16)
-    else
+    elsif value.present?
       value.to_i
+    else
+      nil
     end
   end
 

lib/msf/core/opt_port.rb

@@ -13,7 +13,7 @@ def type
   end
 
   def valid?(value, check_empty: true)
-    port = normalize(value)
+    port = normalize(value).to_i
     super && port <= 65535 && port >= 0
   end
 end