minor changes in try and catch

theano/gof/opt.py

@@ -885,8 +885,7 @@ class MergeOptimizer(Optimizer):
 
                 try:
                     fgraph.replace_all_validate(pairs, 'MergeOptimizer')
-                except Exception as ex:
-                    if type(ex) is InconsistencyError:
+                except InconsistencyError:
                     success = False
                     nb_fail += 1
                     fgraph.merge_feature.blacklist.append(