SLING-7046: Run the Sling ITs with Java 9

Add --add-modules java.se.ee when running on java9
diff --git a/pom.xml b/pom.xml
index 24e3659..99b6fd4 100644
--- a/pom.xml
+++ b/pom.xml
@@ -197,6 +197,23 @@
                 <http.base.path>${project.build.finalName}</http.base.path>
             </properties>
         </profile>
+        <profile>
+            <id>java9</id>
+            <activation>
+                <jdk>9</jdk>
+            </activation>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.eclipse.jetty</groupId>
+                        <artifactId>jetty-maven-plugin</artifactId>
+                        <configuration>
+                            <jvmArgs>--add-modules=java.se.ee</jvmArgs>
+                        </configuration>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
     </profiles>
 
     <dependencies>