Stop logging existing artifacts as Warning

We don't really care if they already exist.

Solves: Jira GER-2216
Change-Id: Ie41a8b0ac1330db0b1c2f3ac0131f944aeb64f2e

src/main/java/com/googlesource/gerrit/plugins/eventseiffel/parsing/EiffelEventParserImpl.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/eventseiffel/parsing/EiffelEventParserImpl.java b/src/main/java/com/googlesource/gerrit/plugins/eventseiffel/parsing/EiffelEventParserImpl.java
index d0e5267..a7ac4aa 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/eventseiffel/parsing/EiffelEventParserImpl.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/eventseiffel/parsing/EiffelEventParserImpl.java
@@ -303,8 +303,7 @@
         }
       } else {
         /* Artc event has already been created */
-        logger.atWarning().log(
-            "Event Artc has already been created for: %s, %s", repoName, tagName);
+        logger.atFine().log("Event Artc has already been created for: %s, %s", repoName, tagName);
       }
     } catch (EiffelEventIdLookupException | InterruptedException e) {
       throw new EventParsingException(