fix: sub1/pom.xml to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JAVA-COMTHOUGHTWORKSXSTREAM-1294540

sub1/pom.xml

@@ -35,7 +35,7 @@
 <dependency><groupId>commons-logging</groupId><artifactId>commons-logging-api</artifactId><version>1.1</version></dependency>
 <dependency><groupId>commons-logging</groupId><artifactId>commons-logging</artifactId><version>1.1</version></dependency>
 <dependency><groupId>commons-pool</groupId><artifactId>commons-pool</artifactId><version>1.5.4</version></dependency>
-<dependency><groupId>com.thoughtworks.xstream</groupId><artifactId>xstream</artifactId><version>1.3.1</version></dependency>
+<dependency><groupId>com.thoughtworks.xstream</groupId><artifactId>xstream</artifactId><version>1.4.17</version></dependency>
 <dependency><groupId>io.netty</groupId><artifactId>netty-all</artifactId><version>4.0.26.Final</version></dependency>
 <dependency><groupId>javassist</groupId><artifactId>javassist</artifactId><version>3.9.0.GA</version></dependency>
 <dependency><groupId>javax.inject</groupId><artifactId>javax.inject</artifactId><version>1</version></dependency>