http_filter complete example breaking

When capturing http traffic using the http-parse-complete.py script, the program crashes.
```bash
sudo python http-parse-complete.py -i lo
[sudo] password for srdan:
binding socket to 'lo'
Traceback (most recent call last):
File "http-parse-complete.py", line 190, in
ip_src = int(toHex(ip_src_str),16)
File "http-parse-complete.py", line 37, in toHex
hv = hex(ord(ch)).replace('0x', '')
TypeError: ord() expected string of length 1, but int found
```

Running on top of Ubuntu 18.04

Inspect http-parse-complete.py, especially toHex at line 37 and the call around line 190; reproduce the failure with the Ubuntu 18.04 command shown. Determine why toHex receives an int instead of a one-character string, then rerun the example to verify HTTP capture no longer crashes.

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