add missing curly braces to fix syntax errors in phpunit test

[ehsan42]

Following errors occur without curly braces when running phpunit test for 'walkthrough_test.php'

stderr: 'PHP Parse error: syntax error, unexpected '';'', expecting '')'' in /var/www/html/question/type/drawing/tests/walkthrough_test.php on line 60' stderr: 'PHP Parse error: syntax error, unexpected '';'', expecting '')'' in /var/www/html/question/type/drawing/tests/walkthrough_test.php on line 69' stderr: 'PHP Parse error: syntax error, unexpected '';'', expecting '')'' in /var/www/html/question/type/drawing/tests/walkthrough_test.php on line 77'