Revert "maven-shade-plugin" to "v.3.5.1", as the Jenkins instance, us…

…ed to build and generate the release, has an older version of maven, which is not supported by the plugin's "v.3.5.2" onwards.

pom.xml

@@ -25,7 +25,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-shade-plugin</artifactId>
-        <version>3.5.2</version>
+        <version>3.5.1</version>
         <!-- DO NOT UPDATE until the Jenkins-instance has its "maven" package updated. Otherwise, the release will not be able to be deployed on Nexus repository. -->
         <executions>
           <execution>