conf: Update copyright

Will Binns · Will Binns · commit 1d21308cb546 · 2020-05-17T19:11:58.000+02:00
diff --git a/conf.py b/conf.py
@@ -19,7 +19,7 @@
 # -- Project information -----------------------------------------------------
 
 project = u'Bitcoin'
-copyright = u'Bitcoin Project 2009-2019'
+copyright = u'Bitcoin Project 2009-2020'
 author = u'Bitcoin Developer Documentation'
 
 # The short X.Y version
