fix: dropbear/network boot ordering — dropbear starts without network

- dropbear: custom init removes 'need net', only needs localmount + bee-sshsetup
- bee-network: removed 'before dropbear' dependency
- bee-network.sh: removed set -e so single iface failure does not abort script

iso/overlay-debug/etc/init.d/bee-network

@@ -5,7 +5,6 @@ description="Bee: bring up network interfaces via DHCP"
 depend() {
     need localmount
     before bee-audit-debug
-    before dropbear
 }
 
 start() {