lib/screenshot.js: remove use of utils module
lib/screenshot.js: remove use of utils module

gunesacar/tor-browser-bundle-testsuite,gunesacar/tor-browser-bundle-testsuite,gunesacar/tor-browser-bundle-testsuite,boklm/tbb-testsuite,gunesacar/tor-browser-bundle-testsuite,boklm/tbb-testsuite,boklm/tbb-testsuite,boklm/tbb-testsuite,boklm/tbb-testsuite