Fix error in detecting duplicated postsynaptic connectors.
Fix error in detecting duplicated postsynaptic connectors.

htem/CATMAID,fzadow/CATMAID,htem/CATMAID,fzadow/CATMAID,fzadow/CATMAID,fzadow/CATMAID,htem/CATMAID,htem/CATMAID