www/firefox-esr: drop unnecessary WAYLAND build fix since r482310

$ make patch

> Applying FreeBSD patches for firefox-esr-60.3.0,1

No such line 323 in input file, ignoring
Ignoring previously applied (or reversed) patch.
1 out of 1 hunks ignored--saving rejects to widget/xremoteclient/DBusRemoteClient.cpp.rej

> FreeBSD patch patch-bug1474265 failed to apply cleanly.

PR: 1474265
Reported by: pkg-fallout