Bump spring-security-oauth2

Bumps [spring-security-oauth2](https://github.com/SpringSource/spring-security-oauth) from 2.0.3.RELEASE to 2.0.18.RELEASE.
- [Release notes](https://github.com/SpringSource/spring-security-oauth/releases)
- [Commits](spring-attic/spring-security-oauth@2.0.3.RELEASE...2.0.18.RELEASE)

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

Author: dependabot[bot]

custom-data-connector/postgresdb-ref-impl-data-connector/pom.xml

@@ -294,7 +294,7 @@
         <dependency>
             <groupId>org.springframework.security.oauth</groupId>
             <artifactId>spring-security-oauth2</artifactId>
-            <version>2.0.3.RELEASE</version>
+            <version>2.0.18.RELEASE</version>
         </dependency>
         <!-- logging -->
         <dependency>