make sure that we don't truncate the stack trace and cause false test failures when the test is executed in a directory with long path

Author: Tyrael

run-tests.php

@@ -240,6 +240,7 @@ function verify_config()
 		'ignore_repeated_errors=0',
 		'precision=14',
 		'memory_limit=128M',
+		'log_errors_max_len=0',
 	);
 
 function write_information($show_html)