security/keepassxc: Unbreak build without BROWSER

> Registering installation for keepassxc-2.3.1

pkg-static: Unable to access file /usr/ports/security/keepassxc/work/stage/usr/local/bin/keepassxc-proxy:No such file or directory

• Error code 74

PR: 228224
Submitted by: Dmitri Goutnik <dg@syrec.org>