Bump spring-core in /web/javamoney-tradingapp

Bumps [spring-core](https://github.com/spring-projects/spring-framework) from 4.3.20.RELEASE to 4.3.21.RELEASE.
- [Release notes](https://github.com/spring-projects/spring-framework/releases)
- [Commits](spring-projects/spring-framework@v4.3.20.RELEASE...v4.3.21.RELEASE)

Signed-off-by: dependabot[bot] <support@github.com>

web/javamoney-tradingapp/pom.xml

@@ -12,7 +12,7 @@
 	<name>Java Money and Currency Web Spring Trading App</name>
 	<properties>
 		<!-- Spring version -->
-		<version.spring>4.3.20.RELEASE</version.spring>
+		<version.spring>4.3.21.RELEASE</version.spring>
 		<!-- Spring Third Party dependencies -->
 		<version.aopalliance>1.0.1-SNAPSHOT</version.aopalliance>
 		<!-- Third Party dependencies -->