change range type to list because deleting range element is illegal

Process AlignMultiprocessed-3:
Traceback (most recent call last):
  File "/usr/local/lib/python3.4/multiprocessing/process.py", line 254, in _bootstrap
    self.run()
  File "bleualign.py", line 1137, in run
    self.multialign = self.process(sourcelist,targetlist,translist1,translist2)
  File "bleualign.py", line 380, in process
    phase1.append(self.align(translist, raw_targetlist))
  File "bleualign.py", line 444, in align
    self.gapfinder(translist, targetlist)
  File "bleualign.py", line 612, in gapfinder
    lastpair = self.gapfiller(sourcegap, targetgap, lastpair, ((src,),(target,)), translist, targetlist)
  File "bleualign.py", line 757, in gapfiller
    del(targetgap[targetgap.index(i)])
TypeError: 'range' object doesn't support item deletion