Revert "Partially disable the Tor Browser window resizing feature."

This reverts commit 2f16f2d1.

In the final Tor Browser 5.5 release the window resizing issue that
caused issues for us in the automated test suite should be fixed.

Will-fix: #10892

config/chroot_local-includes/etc/tor-browser/profile/preferences/0000tails.js

@@ -102,9 +102,3 @@ pref("browser.download.panel.shown", true);
 // open external applications, so let's not offer the option to the user,
 // and instead only propose them to save downloaded files.
 pref("browser.download.forbid_open_with", true);
-
-// The window resizing feature in Tor Browser 5.5a6 is a bit crazy,
-// causing frequent resizing of the window at inconvenient times. In
-// the automated test suite this results in misclicks because some
-// targets move (due to this window resizing) suddenly.
-pref("extensions.torbutton.resize_windows", false);