Only append default value in spatial reference select if spatial uri is not required

ckanext/odsh/helpers.py

@@ -731,6 +731,10 @@ def get_spatial_for_selection():
         spatial_mapping = list(cr)
 
     unique_mapping = []
+    require_spatial_uri = toolkit.asbool(
+        toolkit.config.get('ckanext.odsh.require_spatial_uri', False)
+    )
+    if not require_spatial_uri:
         unique_mapping.append({'value': toolkit._('Select spatial reference..'), 'key': ''})
     seen_values = set()
     for key, value, _ in spatial_mapping: