fix: config-client/pom.xml to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JAVA-COMFASTERXMLJACKSONCORE-7569538

Author: snyk-bot

config-client/pom.xml

@@ -248,7 +248,7 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <swagger-core-version>1.5.24</swagger-core-version>
         <jersey-version>2.29.1</jersey-version>
-        <jackson-version>2.14.0</jackson-version>
+        <jackson-version>2.15.0</jackson-version>
         <maven-plugin-version>1.0.0</maven-plugin-version>
         <junit-version>4.13.1</junit-version>
     </properties>