compile observation convters with quad_utils only for threed_sphere

The converters in the repo all build succesfully without this change,
because they all use threed_sphere location_mod. However maybe there
are some converters in the wild that do not use threed_sphere.

Author: hkershaw-brown

build_templates/buildconvfunctions.sh

@@ -106,7 +106,7 @@ local modelsrc="$DART/models/template/model_mod.f90"
 local loc="$DART/assimilation_code/location/$LOCATION \
           $DART/assimilation_code/location/utilities/ \
           $DART/models/model_mod_tools/test_interpolate_$LOCATION.f90"
-local misc="$DART/models/utilities/ \
+local misc="$DART/models/utilities/default_model_mod.f90 \
             $DART/models/model_mod_tools/model_check_utilities_mod.f90 \
             $DART/observations/forward_operators/obs_def_mod.f90 \
             $DART//observations/forward_operators/obs_def_utilities_mod.f90 \
@@ -139,7 +139,12 @@ else #nompi
    core=${core//$winf08/}
 fi
 
-convsrc="${core} ${conv} ${obserrsrc} ${modelsrc} ${misc} ${loc}"
+quad=""
+if [ "$LOCATION" == "threed_sphere" ]; then
+   quad="$DART/models/utilities/quad_utils_mod.f90"
+fi
+
+convsrc="${core} ${conv} ${obserrsrc} ${modelsrc} ${misc} ${loc} ${quad}"
 
 # remove nuisance files
 nuisance=(\