TaskTree: remove 'ERROR:' prefix from log statement

It is redundant as logging level is added automatically by the logging
library.

Change-Id: Ie7e8186ba3040d9e48e584f2f4c4aad2cf5d28fd

src/main/java/com/googlesource/gerrit/plugins/task/TaskTree.java

diff --git a/src/main/java/com/googlesource/gerrit/plugins/task/TaskTree.java b/src/main/java/com/googlesource/gerrit/plugins/task/TaskTree.java
index cb7e2d4..7079918 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/task/TaskTree.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/task/TaskTree.java
@@ -261,7 +261,7 @@
           return;
         }
       } catch (StorageException e) {
-        log.atSevere().withCause(e).log("ERROR: running changes query: %s", namesFactory.changes);
+        log.atSevere().withCause(e).log("Running changes query '%s' failed", namesFactory.changes);
       } catch (QueryParseException e) {
       }
       addSubDefinition(null);