fix: pom.xml to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JAVA-ORGAPACHEHTTPCOMPONENTS-1048058
- https://snyk.io/vuln/SNYK-JAVA-ORGAPACHEKAFKA-1540737

pom.xml

@@ -17,7 +17,7 @@
 
         <slf4j.version>1.7.25</slf4j.version>
 
-        <kafka-connect.version>2.3.0</kafka-connect.version>
+        <kafka-connect.version>2.7.2</kafka-connect.version>
         <!-- NB: must be consistent with version in kafka-connect -->
         <jackson.version>2.11.4</jackson.version>
         <aws-java-sdk.version>1.11.651</aws-java-sdk.version>