Merge #16920: test: Fix extra_args in wallet_import_rescan.py

fa2e038691 test: Fix extra_args in wallet_import_rescan.py (MarcoFalke)

Pull request description:

  Bug introduced by me (🤦‍♂️) in fa25668e1c

  For reference:

  ```
  >>> a = [[]]*2
  >>> a[0] += ['ONE']
  >>> a
  [['ONE'], ['ONE']]

  >>> a = [[] for _ in range(2)]
  >>> a[0] += ['ONE']
  >>> a
  [['ONE'], []]

ACKs for top commit:
  theStack:
    utACK fa2e038

Tree-SHA512: 7d75a0d06233d013d62198ea95793612242254d5d90f393d01b2beef5abc78d6e85c796532311638f16cfed3b66a7ae41a108c0fe6f0f5d7f6616b042c670df7

test/functional/wallet_import_rescan.py

@@ -150,7 +150,7 @@ class ImportRescanTest(BitcoinTestFramework):
         self.skip_if_no_wallet()
 
     def setup_network(self):
-        self.extra_args = [[]] * self.num_nodes
+        self.extra_args = [[] for _ in range(self.num_nodes)]
         for i, import_node in enumerate(IMPORT_NODES, 2):
             if import_node.prune:
                 self.extra_args[i] += ["-prune=1"]