Add missing licensing data #49

Signed-off-by: Mārtiņš Avots <martins.avots@splitcells.net>

Author: martins-avots

pom.xml

@@ -1,5 +1,9 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <!--
+        SPDX-License-Identifier: EPL-2.0 OR GPL-2.0-or-later
+        SPDX-FileCopyrightText: Contributors To The `net.splitcells.*` Projects
+    -->
     <modelVersion>4.0.0</modelVersion>
     <artifactId>network.hub.root</artifactId>
     <packaging>pom</packaging>