qa: Avoid start/stop of the network thread mid-test

test/functional/p2p_fingerprint.py

@@ -18,7 +18,6 @@ from test_framework.mininode import (
     msg_block,
     msg_getdata,
     msg_getheaders,
-    network_thread_start,
     wait_until,
 )
 from test_framework.test_framework import BitcoinTestFramework
@@ -76,8 +75,6 @@ class P2PFingerprintTest(BitcoinTestFramework):
     # last month but that have over a month's worth of work are also withheld.
     def run_test(self):
         node0 = self.nodes[0].add_p2p_connection(P2PInterface())
-
-        network_thread_start()
         node0.wait_for_verack()
 
         # Set node time to 60 days ago