v5.3.9.RELEASE

Change log:

ff63250 (5.3.x) Update dependencies; prepare for release
ef79bb7 Fix generics for customizeMonoReply()
c70c98b GH-3610: Fix WebFluxMH for error handling
125ac45 (djgraff209/5.3.x) Fix pattern how Lock.unlock() is used
9ebe1b3 Make MessageHistory JSON-serializable
e714f69 GH-3589: Reduce Delay on NIO Connection
1d769b8 Fix SourcePollingChAdFB autoStartup propagation
37e6457 Remove unused imports
46f83f7 Fix NPE for @Indexed in the MessagingGatewayReg
87e11d2 Fix CORS registration for IntGraphController