Bug 1535645 - skipped browser_formdata_format.js on linux not debug r=jmaher

Differential Revision: https://phabricator.services.mozilla.com/D31003

--HG--
extra : moz-landing-system : lando

browser/components/sessionstore/test/browser.ini

@@ -100,6 +100,7 @@ skip-if = (os == 'win') # bug 1331853
 skip-if = (verify && debug)
 [browser_formdata_cc.js]
 [browser_formdata_format.js]
+skip-if = !debug && (os == 'linux') # Bug 1535645
 [browser_formdata_password.js]
 support-files = file_formdata_password.html
 [browser_formdata_xpath.js]