[qa] util: Move wait_bitcoinds() into stop_nodes()

qa/rpc-tests/rpcbind_test.py

@@ -40,7 +40,6 @@ class RPCBindTest(BitcoinTestFramework):
             assert_equal(set(get_bind_addrs(pid)), set(expected))
         finally:
             stop_nodes(self.nodes)
-            wait_bitcoinds()
 
     def run_allowip_test(self, allow_ips, rpchost, rpcport):
         '''
@@ -56,7 +55,6 @@ class RPCBindTest(BitcoinTestFramework):
         finally:
             node = None # make sure connection will be garbage collected and closed
             stop_nodes(self.nodes)
-            wait_bitcoinds()
 
     def run_test(self):
         # due to OS-specific network stats queries, this test works only on Linux