tests: don't wait for lianad to log on shutdown

It seems to be causing some races that i don't want to be investigating
at the moment. It's redundant anyways as we are already checking for the
return code of the process.

tests/test_framework/lianad.py

@@ -127,9 +127,6 @@ class Lianad(TailableProc):
     def stop(self, timeout=5):
         try:
             self.rpc.stop()
-            self.wait_for_log(
-                "Stopping the liana daemon.",
-            )
             self.proc.wait(timeout)
         except Exception as e:
             logging.error(f"{self.prefix} : error when calling stop: '{e}'")