Change erroneous loose comparison to strict comparison in tab panels master
Summary: Fix a loose comparison causing a bug when comparing the selected tab (0) with a tab which has an alphanumeric ID which doesn't begin with an integer. E.g., `(0 == 'kq3p37awi2n5')` is true in PHP 7.4 and below, this can sometimes cause multiple tabs to be displayed when a tab panel is first loaded onto a page: {F278735} Test Plan: Create a tab panel with at least 3 tabs, add a couple more and ensure that multiple tabs aren't loaded. Reviewers: O1 Blessed Committers, valerio.bozzolan, Cigaryno, avivey Reviewed By: O1 Blessed Committers, valerio.bozzolan, Cigaryno, avivey Subscribers: speck, tobiaswiese, valerio.bozzolan, Matthew, Cigaryno Maniphest Tasks: T15146 Differential Revision: https://we.phorge.it/D25067