Suppress deprecation warning in ssh command module handler

The deprecated method is intentionally called for backwards
compatibility with plugins that did not yet update.

Change-Id: I06192b872c8f3ee6c30cd354afdb1e7d1ca42942

gerrit-sshd/src/main/java/com/google/gerrit/sshd/CommandModule.java

@@ -98,6 +98,7 @@ public abstract class CommandModule extends AbstractModule {
     bind(Commands.key(parent, name, description(meta))).to(clazz);
   }
 
+  @SuppressWarnings("deprecation")
   private static String description(CommandMetaData meta) {
     return Objects.firstNonNull(
         Strings.emptyToNull(meta.description()),