fixup! Firefox preference overrides.

BB 43402: set browser.startup.blankWindow false.

browser/app/profile/001-base-profile.js

@@ -454,6 +454,9 @@ pref("privacy.resistFingerprinting.letterboxing.gradient", true);
 pref("privacy.resistFingerprinting.letterboxing.rememberSize", false);
 // tor-browser#41695: How many warnings we show if user closes them without restoring the window size
 pref("privacy.resistFingerprinting.resizeWarnings", 3);
+// tor-browser#43402: Avoid a resize from the skeleton to the newwin size.
+// Should be fixed in ESR-140 with Bug 1448423.
+pref("browser.startup.blankWindow", false);
 // Enforce Network Information API as disabled
 pref("dom.netinfo.enabled", false);
 pref("network.http.referer.defaultPolicy", 2); // Bug 32948: Make referer behavior consistent regardless of private browing mode status