Fix `elabelizer.py` (shifted energy seasons)

Thanks Andrei Erofeev for the bug report

> Скрипт elabelizer.py выдаёт ярлыки и энергии точек,
> смещённые по циклу относительно
> названия сезона? Вот часть вывода:
> LOW2020,     935_89976, 934.705
> HIGH2020,     945_91878, 945.461

elabelizer.py

@@ -3,8 +3,10 @@ The script is for corresponding the elabels from database and compton average me
 run it on cc-8 with the command:
 `python3 elabelizer.py`
 
-If this script is not working properly, try to setup environment firstly with the following command in shell:
+If this script is not working properly, try to setup environment firstly with the following command in bash:
 `source /sl/cmd3/cc8-64/Cmd3Off/tune.cmd3_runs_scripts.sh`
+
+This script is inspired by listoffdata.py script (/sl/cmd3/cc7-64/Cmd3Off/scripts/listoffdata.py)
 """
 
 import os 
@@ -17,7 +19,7 @@ django.setup()
 from cmdweb.apps.cmd3off.energypoints.models import EnergyPoint, Param, ParamData
 from urllib.request import urlopen
 
-    
+
 def retrieve_elabels(startrun, stoprun):
     """Retrieves elabels from database
     
@@ -34,17 +36,22 @@ def retrieve_elabels(startrun, stoprun):
         list of elabels and information about them
         (elabel, firstrun, lastrun, nominal energy, starttime, stoptime, season)
     """
-    elabels = []
-    season = ""
-    for e in EnergyPoint.objects.all():
-        if (e.name).startswith('Season'):
-            season = e.name[7:]
-        if e.startrun >= startrun and e.endrun <= stoprun:
-            elabel_info = (e.name, e.startrun, e.endrun, e.energy, e.starttime, e.endtime, season)
-            if (e.name).startswith('Season'):
-                continue
-            elabels.append(elabel_info)
-    return elabels
+    
+    points, seasons = [], []
+    # Get seasons (they are sorted by date)
+    for e in EnergyPoint.objects.filter(name__startswith="Season"):
+        info = [e.name[7:], e.startrun, e.endrun]
+        seasons.append(info)
+    
+    # Get energy points (they are sorted by date) and match corresponing seasons
+    season_idx = 0
+    for e in EnergyPoint.objects.filter(startrun__gte=startrun, endrun__lte=stoprun):
+        while((e.startrun < seasons[season_idx][1]) or (e.endrun > seasons[season_idx][2])):
+            season_idx+=1
+        info = (e.name, e.startrun, e.endrun, e.energy, e.starttime, e.endtime, seasons[season_idx][0])
+        if not(e.name.startswith("Season")):
+            points.append(info)
+    return points
     
 def get_available_compton_seasons():
     tables_url = 'https://cmd.inp.nsk.su/~compton/gitlist/compton_tables/raw/dev/tables/'