fix ordering of the sorting options in compounds list

Former-commit-id: 38b80a9cfdb558330ebf6dd07cab8850184b989c

ippisite/ippidb/views.py

 import json
 import math
+from collections import OrderedDict
 
 from django.db.models import Max, Min, Count
 from django.shortcuts import render
@@ -201,7 +202,7 @@ def compound_list(request):
         display = 'v'
     context['display']=display
     compound_fields = {f.name: f.verbose_name for f in Compound._meta.get_fields() if not(f.is_relation)}
-    sort_by_options = {}
+    sort_by_options = OrderedDict()
     for sort_by_option_id in sort_by_option_ids:
         if sort_by_option_id == 'pubs':
             name = 'Number of publications'