[LWIP] Remove `RT_USING_NETUTILS` in LwIP 2.0.2 SConscript.

components/net/lwip-2.0.2/SConscript

@@ -76,11 +76,6 @@ if GetDepend(['RT_LWIP_PPP']):
     src += ppp_src
     path += [GetCurrentDir() + '/src/netif/ppp']
     
-# For testing apps
-if GetDepend(['RT_USING_NETUTILS']):
-    src += Glob('./apps/*.c')
-    stc += Glob('./src/apps/tftp/*.c')
-
 group = DefineGroup('lwIP', src, depend = ['RT_USING_LWIP', 'RT_USING_LWIP202'], CPPPATH = path)
 
 Return('group')