Turn project association message down to debug

This was added with Ifcd75e1665df8090ce8e458afc192275265a61c3 which
adds a create-version-from-property event so that targets can do
things in responses to projects pushing a tag.

If you don't use this event, you shouldn't need to setup the
project-to-ITS mapping.  Currently, this is putting out many ERROR
level messages for people in this situation.

Turn it down to a debug message.

Change-Id: I3a876fa138193cf7f22c34c7997b07097322d5ef
diff --git a/src/main/java/com/googlesource/gerrit/plugins/its/base/workflow/ActionController.java b/src/main/java/com/googlesource/gerrit/plugins/its/base/workflow/ActionController.java
index f9214c6..6a705ec 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/its/base/workflow/ActionController.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/its/base/workflow/ActionController.java
@@ -89,7 +89,7 @@
     }
     if (!projectProperties.containsKey("its-project")) {
       String project = projectProperties.get("project");
-      logger.atSevere().log(
+      logger.atFinest().log(
           "Could not process project event. No its-project associated with project %s. "
               + "Did you forget to configure the ITS project association in project.config?",
           project);