Revert "Revert "urxvt: use chromium as the default browser""

This reverts commit d12c1593eaaf231fe0ea218ff687021f2661add2.

The "disappearing dropdown menu" bug is still there.

Signed-off-by: Emilio G. Cota <cota@braap.org>
Merge branch 'master' into flamenco

Signed-off-by: Emilio G. Cota <cota@braap.org>