Fix in-tree build failure due to FloggerLogString error

Bazel in-tree build started failing with the error: "Arguments
to log(String) must be compile-time constants or parameters annotated
with @CompileTimeConstant. If possible, use Flogger's formatting log
methods instead", after the introduction of change: I6550cca076 in
stable-3.5 branch. Update log(String) arguments to use Flogger's
formatting, so that the bazel in-tree build is successful.

Change-Id: I6c7fbbec26c82e7ec00bcb533d48d8b82d7b5b88
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 cdc0c50..f2e651e 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/task/TaskTree.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/task/TaskTree.java
@@ -450,7 +450,7 @@
             return;
           }
         } catch (StorageException e) {
-          log.atSevere().withCause(e).log("ERROR: running changes query: " + namesFactory.changes);
+          log.atSevere().withCause(e).log("ERROR: running changes query: %s", namesFactory.changes);
         } catch (QueryParseException | ConfigInvalidException e) {
         }
         addInvalidNode();