Fix performance monitor display

I had the following issue:
```
Exception in thread Thread-7:
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.7/threading.py", line 763, in run
    self.__target(*self.__args, **self.__kwargs)
  File "./src/OXM/oxcSERVER.py", line 479, in update_performance
    if ds[name[:3]].count([name, desc]) == 0:
UnboundLocalError: local variable 'name' referenced before assignment
```

This is fixed by this pull-request.
If the trailing whitespace changes are not wanted I'll revert them.

Cheers :beers: