MT#61856 docs: print actual year in copyright

Make the year's value automatic.

Change-Id: I6b1ab23144c758aa047cdcbaf26ba86745d150c9

docs/conf.py

@@ -6,8 +6,10 @@
 # -- Project information -----------------------------------------------------
 # https://www.sphinx-doc.org/en/master/usage/configuration.html#project-information
 
+from datetime import date
+
 project = 'rtpengine'
-copyright = '2023, Sipwise'
+copyright = str(date.today().year) + ', Sipwise'
 author = 'Sipwise'
 release = 'master'