fixed PHP 7.4 support

CHANGELOG

@@ -1,5 +1,6 @@
 * 1.41.0 (2019-XX-XX)
 
+ * fixed support for PHP 7.4
  * added "filter", "map", and "reduce" filters (and support for arrow functions)
  * fixed partial output leak when a PHP fatal error occurs
  * optimized context access on PHP 7.4

src/Lexer.php

@@ -262,7 +262,7 @@ class Lexer implements \Twig_LexerInterface
             if ($this->options['whitespace_trim'] === $this->positions[2][$this->position][0]) {
                 // whitespace_trim detected ({%-, {{- or {#-)
                 $text = rtrim($text);
-            } else {
+            } elseif ($this->options['whitespace_line_trim'] === $this->positions[2][$this->position][0]) {
                 // whitespace_line_trim detected ({%~, {{~ or {#~)
                 // don't trim \r and \n
                 $text = rtrim($text, " \t\0\x0B");