cmd/mbf: pick up $TERM

This improves behaviour of some programs.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/mbf/main.go

@@ -618,6 +618,9 @@ func main() {
 				z.Hostname = "localhost"
 				z.Uid, z.Gid = (1<<10)-1, (1<<10)-1
 				z.Stdin, z.Stdout, z.Stderr = os.Stdin, os.Stdout, os.Stderr
+				if s, ok := os.LookupEnv("TERM"); ok {
+					z.Env = append(z.Env, "TERM="+s)
+				}
 
 				var tempdir *check.Absolute
 				if s, err := filepath.Abs(os.TempDir()); err != nil {