Minor Python cleanups to make flake8 pass with the new rules enabled

test/functional/wallet_importprunedfunds.py

@@ -16,7 +16,7 @@ class ImportPrunedFundsTest(BitcoinTestFramework):
         self.nodes[0].generate(101)
 
         self.sync_all()
-        
+
         # address
         address1 = self.nodes[0].getnewaddress()
         # pubkey