recompressTracked.php: Fix typehint of RecompressTracked::dispatch()

Follows-up 4a55e578ff. This must be the same type as
RecompressTracked::dispatchToReplica().

Caught by PhanTypeMismatchArgument, to be enabled in I34d65fe3ff1916f.

Change-Id: Ifff0d92752e6664d7745efeb4840c8b5ddb974a4

maintenance/storage/recompressTracked.php

@@ -275,7 +275,7 @@ class RecompressTracked {
 	/**
 	 * Dispatch a command to the next available replica DB.
 	 * This may block until a replica DB finishes its work and becomes available.
-	 * @param array ...$args
+	 * @param array|string ...$args
 	 */
 	function dispatch( ...$args ) {
 		$pipes = $this->replicaPipes;