Drop obsolete customization to hide the "Tor" section in preferences
32a2cf0fc9dc3c9e00d93be816ae5013f66b4468 should not be necessary anymore with Tor Browser 9.0.1 and newer: https://trac.torproject.org/projects/tor/ticket/32210.
Revert "Hide all Tor connection-related settings in about:preferences in all browsers" (refs: #17214)
Tor Browser 9.0.1 and newer hide these settings when TOR_SKIP_LAUNCH=1 is set,
which is the case for our browsers:
This reverts commit 32a2cf0fc9dc3c9e00d93be816ae5013f66b4468.