vlkb-obscore: if surveys::rest_frequency=0 insert NULL to avoid Inf when calc band (em_min/max)

data-access/engine/src/vlkb-obscore/src/database/SqlSchema_INSERT.cpp

@@ -316,7 +316,7 @@ void SqlSchema_INSERT::appendRow(
       {
          const double SPEED_OF_LIGHT{299792458};// [m/s]
          double val{SPEED_OF_LIGHT / rest_frequency};
-         obscoreRow[em_min] = to_string(val); //get_wavelen(EM_PRECISION, hdu.key_values);
+         obscoreRow[em_min] = (rest_frequency==0.0) ? "NULL" : to_string(val); //get_wavelen(EM_PRECISION, hdu.key_values);
       }
       catch(const std::exception&  ex)
       {