Handle PipelineInterpreter.State event to avoid warning in the log

Fixes #236

plugin/src/main/java/org/graylog/plugins/pipelineprocessor/processors/ConfigurationStateUpdater.java

@@ -1,15 +1,13 @@
 package org.graylog.plugins.pipelineprocessor.processors;
 
+import com.codahale.metrics.MetricRegistry;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.HashMultimap;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSetMultimap;
 import com.google.common.collect.Maps;
 import com.google.common.eventbus.EventBus;
 import com.google.common.eventbus.Subscribe;
-
-import com.codahale.metrics.MetricRegistry;
-
 import org.graylog.plugins.pipelineprocessor.ast.Pipeline;
 import org.graylog.plugins.pipelineprocessor.ast.Rule;
 import org.graylog.plugins.pipelineprocessor.codegen.PipelineClassloader;
@@ -26,6 +24,11 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import javax.annotation.Nonnull;
+import javax.inject.Inject;
+import javax.inject.Named;
+import javax.inject.Singleton;
+import javax.tools.ToolProvider;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -34,12 +37,6 @@
 import java.util.concurrent.atomic.AtomicReference;
 import java.util.stream.Collectors;
 
-import javax.annotation.Nonnull;
-import javax.inject.Inject;
-import javax.inject.Named;
-import javax.inject.Singleton;
-import javax.tools.ToolProvider;
-
 import static com.codahale.metrics.MetricRegistry.name;
 
 @Singleton
@@ -218,6 +215,11 @@ public void handlePipelineConnectionChanges(PipelineConnectionsChangedEvent even
         scheduler.schedule(() -> serverEventBus.post(reloadAndSave()), 0, TimeUnit.SECONDS);
     }
 
+    @Subscribe
+    public void handlePipelineStateChange(PipelineInterpreter.State event) {
+        log.debug("Pipeline interpreter state got updated");
+    }
+
     @VisibleForTesting
     PipelineInterpreter.State reload() {
         return reloadAndSave();