Make \0 work as expected

stdplugins/sed.py

@@ -23,7 +23,9 @@ last_msgs = defaultdict(lambda: deque(maxlen=10))
 def doit(chat_id, match, original):
     fr = match.group(1)
     to = match.group(2)
-    to = to.replace('\\/', '/')
+    to = (to
+          .replace('\\/', '/')
+          .replace('\\0', '\\g<0>'))
     try:
         fl = match.group(3)
         if fl is None: