Set as public - resolve_cache_processor

liip_imagine.async.resolve_cache_processor should be public or an exception is thrown when sending enqueue command.

Resources/config/enqueue.xml

@@ -4,7 +4,7 @@
     xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">
 
     <services>
-        <service id="liip_imagine.async.resolve_cache_processor" class="Liip\ImagineBundle\Async\ResolveCacheProcessor">
+        <service id="liip_imagine.async.resolve_cache_processor" class="Liip\ImagineBundle\Async\ResolveCacheProcessor" public="true">
             <argument type="service" id="liip_imagine.filter.manager" />
             <argument type="service" id="liip_imagine.service.filter" />
             <argument type="service" id="enqueue.producer" />