make check_apt_last_update python3 (ubuntu 20.04) ready

#!/usr/bin/env python3
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> # plugin adjusted from python2 to python3 20200603
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__version__ = “0.0.2”
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print(“%sOK: %s” % (check, message))
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print(“%sWARNING: %s” % (check, message))
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print(“%sCRITICAL: %s” % (check, message))
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print(“UNKNOWN: %s” % message)
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> # self.verbosity = int(self.verbosity)
> if self.verbosity == None:
> self.verbosity = 0
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print(“%s” % message)
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line = next(f)
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% (__title__, __version__, __author__))
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print(“Caught Control-C…”)