reorder initialization to make compiler happy

I'm not sure about the reasoning behind the warning, maybe hide
issues due to out-of-bounds writes?

mpeg/dvbstreamdata.h:226: warning: 'DVBStreamData::_dvb_eit_dishnet_long' will be initialized after
mpeg/dvbstreamdata.h:223: warning:   'int DVBStreamData::_dvb_real_network_id'
mpeg/dvbstreamdata.cpp:21: warning:   when initialized here
add newline at end of file