fix initialization of option_validator

When using option_validator to validate config.ini entries for
detectors or extensions, the list of validators was not reset when the
tracker was re-opened.

This led to the second command run in roundup-admin crashing when the
main config.ini file was read. On second tracker open/read
option_validator lists an extension/detector option that doesn't exist
in the main config.ini. When it tried to validate, the missing option
caused a crash.

This only happens if a validator is added in an extension/detector.
If the only validators ae ones for the main config.ini everything
works fine across multiple tracker opens.

Author: rouilj

CHANGES.txt

@@ -81,6 +81,9 @@ Fixed:
 - upgrade from jquery-3.5.1 to jquery-3.6.3. Update user.help.html
   to new version.  (John Rouillard)
 - Dockerfile scanned with hadolint. Fixed multiple issues. (John Rouillard)
+- fix crash due to invalid initialization/reset of configuration.py
+  option_validators. Crashed roundup-admin on second command if an
+  option_validator was added by a detector or extension. (John Rouillard)
 
 Features:
 

roundup/configuration.py

@@ -1756,7 +1756,7 @@ class Config:
 
     # List of option names that need additional validation after
     # all options are loaded.
-    option_validators = []
+    option_validators = None
 
     def __init__(self, config_path=None, layout=None, settings=None):
         """Initialize confing instance
@@ -1782,6 +1782,7 @@ def __init__(self, config_path=None, layout=None, settings=None):
         self.section_descriptions = {}
         self.section_options = {}
         self.options = {}
+        self.option_validators = []
         # add options from the layout structure
         if layout:
             for section in layout: