[Contributing][Code] fix list item terminators

Author: xabbuh

contributing/code/standards.rst

@@ -169,11 +169,11 @@ Structure
 * Use parentheses when instantiating classes regardless of the number of
   arguments the constructor has;
 
-* Exception and error message strings should be concatenated using :phpfunction:`sprintf`.
+* Exception and error message strings should be concatenated using :phpfunction:`sprintf`;
 
 * Calls to :phpfunction:`trigger_error` with type ``E_USER_DEPRECATED`` should be
   switched to opt-in via ``@`` operator.
-  Read more at :ref:`contributing-code-conventions-deprecations`;
+  Read more at :ref:`contributing-code-conventions-deprecations`.
 
 Naming Conventions
 ------------------