test: Fix TypeError in wait_for_debug_log

Traceback:

print_log = " - " + "\n - ".join(log.splitlines())
                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: sequence item 0: expected str instance, bytes found

1 files changed, 1 insertions, 1 deletions

diff --git a/test/functional/test_framework/test_node.py b/test/functional/test_framework/test_node.py
index 882f82e0f2..56abe5f26a 100755
--- a/test/functional/test_framework/test_node.py
+++ b/test/functional/test_framework/test_node.py
@@ -469,7 +469,7 @@ class TestNode():
                 return
 
             if time.time() >= time_end:
-                print_log = " - " + "\n - ".join(log.splitlines())
+                print_log = " - " + "\n - ".join(log.decode("utf8", errors="replace").splitlines())
                 break
 
             # No sleep here because we want to detect the message fragment as fast as