Revert "SLING-7046: Run the Sling ITs with Java 9"

This reverts commit 6504a5c762b9c2b2bb5d50d6047ec809aba7ab8f.

Since the jetty:run-war goal does not support forking, the jvmArgs
parameter did not have any effect.
diff --git a/pom.xml b/pom.xml
index 99b6fd4..24e3659 100644
--- a/pom.xml
+++ b/pom.xml
@@ -197,23 +197,6 @@
                 <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>