fix checksum discrepancy
fix checksum discrepancy

expected
```
vdloo@asuran:~/files/thediff$ cat before.txt | sed 's/,*$//g' | sort | md5sum
1ea5b4f2365c524a86b695b44484464c  -
vdloo@asuran:~/files/thediff$ cat after.txt | sed 's/,*$//g' | sort | md5sum
1ea5b4f2365c524a86b695b44484464c  -
```

before
```
In [2]: from raptiformica.actions.mesh import *

In [3]: calculate_lines_checksum('/home/vdloo/files/thediff/before.txt')
Out[3]: '683c0dc0a56d6e4770f6dfbfdfc3370f6e0f0383'

In [4]: calculate_lines_checksum('/home/vdloo/files/thediff/after.txt')
Out[4]: '83b72f4bebac2c929ecc23996c4182125ee89501'
```

after
```
In [2]: calculate_lines_checksum('/home/vdloo/files/thediff/before.txt')
Out[2]: 'a4e3eb9b78121f87b7659c5a9b1601601a0a1a4f'

In [3]: calculate_lines_checksum('/home/vdloo/files/thediff/after.txt')
Out[3]: 'a4e3eb9b78121f87b7659c5a9b1601601a0a1a4f'
```

vdloo/raptiformica,vdloo/raptiformica,vdloo/raptiformica