Document SetInactiveFlag

Change-Id: Ic96c127840d17277fb36c5c0522a1f87b9053740
diff --git a/java/com/google/gerrit/server/account/SetInactiveFlag.java b/java/com/google/gerrit/server/account/SetInactiveFlag.java
index a6c5d5c..32ed694 100644
--- a/java/com/google/gerrit/server/account/SetInactiveFlag.java
+++ b/java/com/google/gerrit/server/account/SetInactiveFlag.java
@@ -32,6 +32,7 @@
 import java.util.concurrent.atomic.AtomicReference;
 import org.eclipse.jgit.errors.ConfigInvalidException;
 
+/** Toggler for account active state. */
 @Singleton
 public class SetInactiveFlag {
   private final PluginSetContext<AccountActivationValidationListener>