added missing p2pool import to bitcoin.height_tracker

diff --git a/p2pool/bitcoin/height_tracker.py b/p2pool/bitcoin/height_tracker.py
index d22fb7b..3844283 100644 (file)
--- a/p2pool/bitcoin/height_tracker.py
+++ b/p2pool/bitcoin/height_tracker.py
@@ -1,6 +1,7 @@
 from twisted.internet import defer, task
 from twisted.python import log
 
+import p2pool
 from p2pool.bitcoin import data as bitcoin_data
 from p2pool.util import deferral, forest, jsonrpc, variable