lwip: adapt run script to new DHCP behavior

We will always get an IP after the server was started. Therefore, we
have to wait until we see the "got IP" message.

Issue #1327.

repos/libports/run/lwip.run

@@ -180,7 +180,7 @@ append_if [have_spec lan9118] qemu_args " -net nic,model=lan9118 "
 
 append qemu_args " -net user -redir tcp:5555::80 "
 
-run_genode_until {.*Start the server loop \.\.\..*} 30
+run_genode_until {.*got IP address .*\n} 30
 
 if {[have_include "power_on/qemu"]} {
 	set uri "http://localhost:5555/"