Merge pull request rapid7#1296 from wchen-r7/normalize_optport

[FixRM: rapid7#7535] Missing normalize() in OptPort

Author: HD Moore

lib/msf/core/option_container.rb

@@ -302,6 +302,10 @@ def type
 		return 'port'
 	end
 
+	def normalize(value)
+		value.to_i
+	end
+
 	def valid?(value)
 		return false if empty_required_value?(value)