Bump spring-expression from 3.0.6.RELEASE to 5.2.20.RELEASE

Bumps [spring-expression](https://github.com/spring-projects/spring-framework) from 3.0.6.RELEASE to 5.2.20.RELEASE.
- [Release notes](https://github.com/spring-projects/spring-framework/releases)
- [Commits](https://github.com/spring-projects/spring-framework/compare/v3.0.6.RELEASE...v5.2.20.RELEASE)

---
updated-dependencies:
- dependency-name: org.springframework:spring-expression
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
diff --git a/pom.xml b/pom.xml
index d77daa3..2a33321 100644
--- a/pom.xml
+++ b/pom.xml
@@ -104,7 +104,7 @@
         <xfire-version>1.2.5</xfire-version>
         <mavenAssemblyPluginVersion>2.1</mavenAssemblyPluginVersion>
         <xbean-version>3.11.1</xbean-version>
-        <spring-version>3.0.6.RELEASE</spring-version>
+        <spring-version>5.2.20.RELEASE</spring-version>
         <activemq-version>5.5.1</activemq-version>
         <activeio-version>3.1.2</activeio-version>
         <camel-version>2.8.5</camel-version>