[qa] util: Remove unused sync_chain

test/functional/rpc_preciousblock.py

@@ -8,7 +8,6 @@ from test_framework.test_framework import BitcoinTestFramework
 from test_framework.util import (
     assert_equal,
     connect_nodes_bi,
-    sync_chain,
     sync_blocks,
 )
 
@@ -72,7 +71,7 @@ class PreciousTest(BitcoinTestFramework):
         assert_equal(self.nodes[0].getbestblockhash(), hashC)
         self.log.info("Make Node1 prefer block C")
         self.nodes[1].preciousblock(hashC)
-        sync_chain(self.nodes[0:2]) # wait because node 1 may not have downloaded hashC
+        sync_blocks(self.nodes[0:2])  # wait because node 1 may not have downloaded hashC
         assert_equal(self.nodes[1].getbestblockhash(), hashC)
         self.log.info("Make Node1 prefer block G again")
         self.nodes[1].preciousblock(hashG)