Update jasmine2-runner.js

This is a workaround for https://github.com/ariya/phantomjs/issues/12697 which is also used in the guard-jasmine project https://github.com/DawidJanczak/guard-jasmine/commit/04ca925774646bf61394d9a35b2af2043a563879
Merge pull request #9 from sebastianrosik/master

Update jasmine2-runner.js