fc7aad6 framework: Log plugin exception traceback when log level is DEBUG

Authored and Committed by plautrba 4 years ago
    framework: Log plugin exception traceback when log level is DEBUG
    
    Use the following setting to enable traceback logging when there's a 'Plugin
    Exception'.
    
    /etc/setroubleshoot/setroubleshoot.conf:
    [sealert_log]
    level = debug