Use LANG=C to avoid false error due to language

[Marzal]

Some commands could result in empty string when grepping in non-English systems. Like:

netstat -tuln
Conexiones activas de Internet (solo servidores)
Proto  Recib Enviad Dirección local         Dirección remota       Estado      
tcp        0      0 127.0.0.1:3493          0.0.0.0:*              ESCUCHAR

I've tested adding LANG=C at the start of the script and works better.