Reload the artist whitelist file after rolling back changes

As someone was repeatedly running the update-artist-whitelist command they
would previously see a stale version of the artist file since it was hanging
around in memory. This is fixed now.

commandcenter/commands.py

@@ -26,15 +26,20 @@ def update_artist_whitelist():
     cmd = ['git', 'checkout', artists._WHITELIST_FILE]
     exec_and_print(cmd, cwd)
 
+    # This will reload the artist whitelist file
+    # in python memory.
+    artists._init()
+
     for _ in main_generator(rewrite=True):
         yield
 
     # Show changes to the artist whitelist file
     cprint('Changes made to artist whitelist:')
     cmd = ['git', 'diff', artists._WHITELIST_FILE]
     exec_and_print(cmd, cwd)
-    # This will load the new artist whitelist file
-    # into python memory.
+
+    # Once again, this reloads the artist whitelist file
+    # in python memory.
     artists._init()