doc: extend copyright period to 2022

Signed-off-by: Bastian Krause <bst@pengutronix.de>

Author: Bastian-Krause

doc/conf.py

@@ -55,7 +55,7 @@
 
 # General information about the project.
 project = 'labgrid'
-copyright = '2016-2021 Pengutronix, Jan Luebbe and Rouven Czerwinski'
+copyright = '2016-2022 Pengutronix, Jan Luebbe and Rouven Czerwinski'
 author = 'Jan Luebbe, Rouven Czerwinski'
 
 # The version info for the project you're documenting, acts as replacement for