remove unreachable code

Since our version constraint is `^1.37.1|^2.6.2` any Twig version that
is below 2.4.5 must be a Twig 1.x release.

Author: xabbuh

Tests/Node/TransNodeTest.php

@@ -53,12 +53,8 @@ protected function getVariableGetterWithoutStrictCheck($name)
 
     protected function getVariableGetterWithStrictCheck($name)
     {
-        if (Environment::VERSION_ID > 20404) {
-            return sprintf('(isset($context["%s"]) || array_key_exists("%1$s", $context) ? $context["%1$s"] : (function () { throw new Twig_Error_Runtime(\'Variable "%1$s" does not exist.\', 0, $this->source); })())', $name);
-        }
-
         if (Environment::MAJOR_VERSION >= 2) {
-            return sprintf('(isset($context["%s"]) || array_key_exists("%1$s", $context) ? $context["%1$s"] : (function () { throw new Twig_Error_Runtime(\'Variable "%1$s" does not exist.\', 0, $this->getSourceContext()); })())', $name);
+            return sprintf('(isset($context["%s"]) || array_key_exists("%1$s", $context) ? $context["%1$s"] : (function () { throw new Twig_Error_Runtime(\'Variable "%1$s" does not exist.\', 0, $this->source); })())', $name);
         }
 
         if (\PHP_VERSION_ID >= 70000) {