Bad port comparison when srcIp==dstIp

Implemented the algorithm and tested the resulting ids comparing against this repo's python script and also against wireshark's community id analysis tool. My implementation's results seemed to always match wireshark's but not corelight's.

When having same ip addresses for src and dst, the following port values seem to be handled differently by corelight's script:
```
ip_src ip_dest proto(tcp) port_src port_dst community id from coreligh python script community id from wireshark
1.2.3.4 1.2.3.4 6 3344 1122 1:CY1T7/6B7r9W3LMnzSws9RXqqbQ= 1:3seqIXu+5y8sFuE3lLtWR/KnSWo=
1.2.3.4 1.2.3.4 6 1122 3344 1:CY1T7/6B7r9W3LMnzSws9RXqqbQ= 1:3seqIXu+5y8sFuE3lLtWR/KnSWo=
1.2.3.1 1.2.3.1 6 3344 1122 1:jD1eCyop8ZzeL/0xgO58JtpHPLE= 1:GfxcHO3Gsn1cQxpPJoBhxUMcrbU=
1.2.3.4 1.2.3.4 6 5566 7788 1:YZWovxgLMFDntXoQs0LgEGs9QcQ= 1:BjNbSLaYeZZX0M1egqjh1Akg9yw=
1.2.3.4 1.2.3.4 6 6655 8877 1:7hdcx4YnNvllNYNSbtSzegQFnjg= 1:miYC8NFsg/sTi5HwWjjyifbbp+8=
```
Port combinations like: {1122, 44424}, {334, 44424}, {1133, 2244}, {8899, 1199} didn't seem to cause any issues though.

In function `is_ordered()`, changing port comparison in the return to:
```
int.from_bytes(nbo.sport, 'little') < int.from_bytes(nbo.dport, 'little')
```

seems to get the cases I tried to match.