prevent running migrations if is_fresh_install

+ fix: sqlite3.ProgrammingError: Cannot operate on a closed cursor on ProcessAlbumColors()
+ move processing artist images from periodic_scans to Populate
+ bump hash string limit from 7 to 10
+ add last_mod property to database
+ fix: TypeError: '<' not supported between instances of 'int' and 'str' on album page

app/periodic_scan.py

@@ -2,11 +2,8 @@
 This module contains functions for the server
 """
 import time
-from requests import ReadTimeout
-from requests import ConnectionError as RequestConnectionError
 
 from app.logger import log
-from app.lib.artistlib import CheckArtistImages
 from app.lib.populate import Populate, PopulateCancelledError
 
 from app.utils.generators import get_random_str
@@ -30,13 +27,5 @@ def run_periodic_scans():
         except PopulateCancelledError:
             pass
 
-        if Ping()():
-            try:
-                CheckArtistImages()
-            except (RequestConnectionError, ReadTimeout):
-                log.error(
-                    "Internet connection lost. Downloading artist images stopped."
-                )
-
         sleep_time = get_scan_sleep_time()
         time.sleep(sleep_time)