minor symfony#6096 [Contributing] update year in license (xabbuh)

This PR was merged into the 2.3 branch.

Discussion
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[Contributing] update year in license

Commits
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37f828b update year in license

Author: wouterj

contributing/code/license.rst

@@ -16,7 +16,7 @@ According to `Uncyclopedia`_:
 The License
 -----------
 
-Copyright (c) 2004-2015 Fabien Potencier
+Copyright (c) 2004-2016 Fabien Potencier
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal