Update to maintenance.py

After my Sqlite3 db got huge, I checked the logs and found that the maint script was generating errors.

- changed 'purge_flights = row' to 'purge_flights = int(row[0])'
this explicitly gets the first result in the array and casts it to an int as the value returned from the DB (column type is TEXT') is unicode

Have NOT tested on MySQL

build/portal/python/maintenance.py

@@ -64,26 +64,26 @@ while True:
     cursor.execute("SELECT value FROM adsb_settings WHERE name = 'purgeFlights'")
     row = cursor.fetchone()
     if row:
-        purge_flights = row
+        purge_flights = int(row[0])
 
     purge_positions = False
     # MySQL and SQLite
     cursor.execute("SELECT value FROM adsb_settings WHERE name = 'purgePositions'")
     row = cursor.fetchone()
     if row:
-        purge_positions = row
+        purge_positions = int(row[0])
 
     purge_days_old = False
     # MySQL and SQLite
     cursor.execute("SELECT value FROM adsb_settings WHERE name = 'purgeDaysOld'")
     row = cursor.fetchone()
     if row:
-        purge_days_old = row
+        purge_days_old = int(row[0])
 
     ## Create the purge date from the age specified.
 
     if purge_days_old:
-        purge_datetime = datetime.datetime.utcnow() - timedelta(days=purge_days_old)
+        purge_datetime = datetime.datetime.utcnow() - datetime.timedelta(days=purge_days_old)
         purge_date = purge_datetime.strftime("%Y/%m/%d %H:%M:%S")
     else:
         purge_datetime = None