Add CHANGES entry

4903.	[bug]		"check-mx fail;" did not prevent MX records containing
			IP addresses from being added to a zone by a dynamic
			update. [GL #112]

CHANGES

+4903.	[bug]		"check-mx fail;" did not prevent MX records containing
+			IP addresses from being added to a zone by a dynamic
+			update. [GL #112]
+
 4902.	[test]		Improved the reliability of the 'ixfr' system
 			test. [GL #66]