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

This reverts commit 4e09e4641688d9ee01a7cbda36b611ce2e69d36f.

Firefox seems to work fine now.

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

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