[views] remove reference to the MAPPING_CHECKERS dict (closes #3810219) Was removed by by the changeset 65d93a4fd11c ([multi-sources-removal] Drop pyrorql and zmqrql sources)

from os.path import join
assert __file__.endswith(join('scripts', 'script2.py')), __file__
assert '__main__' == __name__, __name__
assert ['-v'] == __args__, __args__