Expose number of currently active watchers in stats1.6.11

The stat key `log_watchers` indicates the number of active connected
`watch` clients.

1 files changed, 1 insertions, 0 deletions

diff --git a/logger.h b/logger.h
index 4015206..039f443 100644
--- a/logger.h
+++ b/logger.h
@@ -170,6 +170,7 @@ struct logger_stats {
     uint64_t worker_written;
     uint64_t watcher_skipped;
     uint64_t watcher_sent;
+    uint64_t watcher_count;
 };
 
 extern pthread_key_t logger_key;