Use a constant for copyright year in docs.

docs/conf.py

@@ -11,7 +11,6 @@
 import os
 import sys
 import sphinx_rtd_theme
-import datetime
 
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
@@ -56,7 +55,7 @@
 
 # General information about the project.
 project = 'Segno'
-copyright = '2016 - {0} Lars Heuer -- "QR Code" and "Micro QR Code" are registered trademarks of DENSO WAVE INCORPORATED.'.format(datetime.datetime.now().year)
+copyright = '2016 - 2021 Lars Heuer -- "QR Code" and "Micro QR Code" are registered trademarks of DENSO WAVE INCORPORATED.'
 author = 'Lars Heuer'
 
 # The version info for the project you're documenting, acts as replacement for