test: Use rehash() in outbound eviction block-relay

Ensure that tip_header.rehash() is used instead of tip_header.hash, which is None when the header is deserialized from hex.

This avoids depending on wait_for_getheaders() falling back to any received message, making the test more explicit and robust.

test/functional/p2p_outbound_eviction.py

@@ -235,7 +235,7 @@ class P2POutEvict(BitcoinTestFramework):
         cur_mock_time += (CHAIN_SYNC_TIMEOUT + 1)
         node.setmocktime(cur_mock_time)
         peer.sync_with_ping()
-        peer.wait_for_getheaders(block_hash=tip_header.hash)
+        peer.wait_for_getheaders(block_hash=tip_header.rehash())
         cur_mock_time += (HEADERS_RESPONSE_TIME + 1)
         node.setmocktime(cur_mock_time)
         self.log.info("Test that the peer gets evicted")