Set java.logging as optional module (#183)

Commons Logging has a fallback simple logger that is used if the
`java.util.logging` package is not present.

Originally this only could happen with Java 1.3, but sinc Java 9 the
user can disable the `java.logging` JPMS module. Commons Logging will
work anyway.

This PR slightly modifies the inherited Moditect configuration to add a
`static` (i.e. optional) modifier to the `java.logging` module.

pom.xml

@@ -332,6 +332,26 @@ under the License.
         </configuration>
       </plugin>
 
+      <plugin>
+        <groupId>org.moditect</groupId>
+        <artifactId>moditect-maven-plugin</artifactId>
+        <executions>
+          <execution>
+            <id>add-module-infos</id>
+            <configuration>
+              <module>
+                <moduleInfo>
+                  <requires>
+                    static java.logging;
+                    *;
+                  </requires>
+                </moduleInfo>
+              </module>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+
       <plugin>
         <!--
           - Many of JCL's tests use tricky techniques to place the generated