autotest: restore timeout in log download

this removes the debug code now that the issue has been found (it was
an old version of pymavlink causing the problem)

Tools/autotest/common.py

@@ -250,14 +250,7 @@ def log_download(mavproxy, mav, filename, timeout=360):
     mav.wait_heartbeat()
     mav.wait_heartbeat()
     mavproxy.send("log download latest %s\n" % filename)
-    t1 = time.time()
-    while time.time() - t1 < timeout:
-        try:
-            mavproxy.expect("Finished downloading", timeout=5)
-        except Exception:
-            mavproxy.send("log status\n")
-            continue
-        break
+    mavproxy.expect("Finished downloading", timeout=timeout)
     mavproxy.send("log erase\n")
     mav.wait_heartbeat()
     mav.wait_heartbeat()