Fix java-doc link to AboutSections#SECTION in ISystemInformation

[HannesWell]

The latest I-build failed because of this invalid link

 [ERROR] Failed to execute goal org.apache.maven.plugins:maven-javadoc-plugin:3.10.1:javadoc (attach-javadocs) on project org.eclipse.platform.doc.isv: An error has occurred in Javadoc report generation: 
 [ERROR] Exit code: 1
 [ERROR] /home/jenkins/agent/workspace/Builds/I-build-4.34/eclipse.platform.releng.aggregator/eclipse.platform.releng.aggregator/cje-production/gitCache/eclipse.platform.releng.aggregator/eclipse.platform.common/bundles/org.eclipse.platform.doc.isv/../../../eclipse.platform/runtime/bundles/org.eclipse.e4.core.services/src/org/eclipse/e4/core/services/about/ISystemInformation.java:42: error: reference not found
 [ERROR] 	 * @see #SECTION
 [ERROR] 	        ^
 [ERROR] Note: Custom tags that could override future standard tags:  @Immutable, @provisional, @implSpec, @TrackedGetter, @noextend, @issue, @ThreadSafe, @implNote, @jniclass, @noreference, @noinstantiate, @noimplement, @nooverride, @category. To avoid potential overrides, use at least one period character (.) in custom tag names.
 [ERROR] Note: Custom tags that were not seen:  @Immutable, @provisional, @issue, @category

[HannesWell]

The verification build does not validate this change (otherwise this mistake would have not made it into the master). In the IDE the link now works well.
Therefore I submit this immediately and start a new I-build.