core: force inet_aton argument to string to prevent occasional error on reconnect.

it /should/ always be a string anyway, but sometimes things break with
a TypeError that it is an int instead of the expected string and hangs
up the bot.

src/utils/net.py

@@ -114,7 +114,7 @@ def isIPV4(s):
     0
     """
     try:
-        return bool(socket.inet_aton(s))
+        return bool(socket.inet_aton(str(s)))
     except socket.error:
         return False