RFR: 8248262: Wrong link target in ModuleDescriptor#isAutomatic's API documentation

[Christian Stein]

Fix target in `ModuleDescriptor#isAutomatic`'s API documentation to point to `Modifier.AUTOMATIC`.

https://bugs.openjdk.java.net/browse/JDK-8248262

-------------

Commit messages:
 - Fix link target in ModuleDescriptor#isAutomatic's API documentation

Changes: https://git.openjdk.java.net/jdk/pull/555/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=555&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8248262
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/555.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/555/head:pull/555

PR: https://git.openjdk.java.net/jdk/pull/555