Update copyright year for 2017

(cherry picked from commit 7a1c564203695a98546f31185be71e98749d294d)

conf.py

@@ -23,7 +23,7 @@ master_doc = 'index'
 
 # General information about the project
 project = 'Godot Engine'
-copyright = '2014-2016, Juan Linietsky, Ariel Manzur and the Godot community (CC BY 3.0)'
+copyright = '2014-2017, Juan Linietsky, Ariel Manzur and the Godot community (CC-BY 3.0)'
 author = 'Juan Linietsky, Ariel Manzur and the Godot community'
 
 # Version info for the project, acts as replacement for |version| and |release|