Bug 1588680 - Disable browser_todayPane_visibility.js that fails often in debug. rs=bustage-fix

--HG--
extra : rebase_source : 5b0212e19cb3f9d87fa115c268cd08e782d9ea24
extra : amend_source : 335d41c05d7fd33937f360dfb1915e5f144843e7
extra : histedit_source : d84b64375b3493eb6058564339dd6dc08fef109a

calendar/test/browser/browser.ini

@@ -22,3 +22,4 @@ support-files = data/**
 skip-if = debug
 [browser_todayPane.js]
 [browser_todayPane_visibility.js]
+skip-if = debug