Bump spring-boot-autoconfigure from 1.2.5.RELEASE to 2.4.3

Bumps [spring-boot-autoconfigure](https://github.com/spring-projects/spring-boot) from 1.2.5.RELEASE to 2.4.3.
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v1.2.5.RELEASE...v2.4.3)

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

pom.xml

@@ -39,7 +39,7 @@
     <logging.version>4.9.1</logging.version>
     <guava.version>30.1-jre</guava.version>
     <backo.version>1.0.0</backo.version>
-    <spring.boot.version>1.2.5.RELEASE</spring.boot.version>
+    <spring.boot.version>2.4.3</spring.boot.version>
     <docopt.version>0.6.0.20150202</docopt.version>
 
     <!-- Test Dependencies -->