potential array overrun in dezing_filter.py

The code in the plugin appears to assume that flat and dark have the same number of frames.
If flat has a greater number of frames than dark,this will have potential to fail in a bad way.

50 def pre_process(self):
51 # Apply dezing to dark and flat images (data with image key only)
52 inData = self.get_in_datasets()[0]
53 dark = inData.data.dark()
54 flat = inData.data.flat()
55 logging.info("dezing setup size function for dark %s",(dark.shape,))
56 (retval, self.warnflag, self.errflag) = dezing.setup_size(
57 dark.shape, self.parameters['outlier_mu'], self.pad)
58 pad_list = ((self.pad, self.pad), (0, 0), (0, 0))
59 dark = self._dezing(np.pad(dark, pad_list, mode='edge'))
60 flat = self._dezing(np.pad(flat, pad_list, mode='edge'))