fix max line length

Author: xabbuh

contributing/code/standards.rst

@@ -112,8 +112,8 @@ Structure
 * Add a blank line before ``return`` statements, unless the return is alone
   inside a statement-group (like an ``if`` statement);
 
-* Use just ``return;`` instead of ``return null;`` when a function must return void
-  early;
+* Use just ``return;`` instead of ``return null;`` when a function must return
+  void early;
 
 * Use braces to indicate control structure body regardless of the number of
   statements it contains;