#404 fix using 0 to disable max_deferrals and retry_after

lib/App/Netdisco/Configuration.pm

@@ -181,6 +181,11 @@ setting('workers')->{'timeout'} = setting('timeout')
   if defined setting('timeout')
      and !defined setting('workers')->{'timeout'};
 
+# 0 for workers max_deferrals and retry_after is like disabling
+# but we need to fake it with special values
+setting('workers')->{'max_deferrals'} ||= (2**30);
+setting('workers')->{'retry_after'}   ||= '100 years';
+
 # schedule expire used to be called expiry
 setting('schedule')->{expire} ||= setting('schedule')->{expiry}
   if setting('schedule') and exists setting('schedule')->{expiry};