init: exclude schroot mountpoint from socket search, improve performance. (#1836)

This fixes minute long start-up hangs when using distrobox on a host
that has active schroot mounts.

Signed-off-by: Stefan Kerkmann <s.kerkmann@pengutronix.de>

distrobox-init

@@ -1925,6 +1925,7 @@ host_sockets="$(find /run/host/run \
 	-name 'user' -prune -o \
 	-name 'bees' -prune -o \
 	-name 'nscd' -prune -o \
+	-name 'schroot' -prune -o \
 	-name 'system_bus_socket' -prune -o \
 	-type s -print \
 	2> /dev/null || :)"