archivebot: consistent handling of on-site configuration errors
archivebot: consistent handling of on-site configuration errors

All ending of a run on a page will cause a sleep, with a configurable duration.

Previously a normal return from run() causes a 10-sec sleep,
while an exception causes no sleep and a stack trace will be printed.

Change-Id: I2cbb4026e331d0e23e07c1c8aef344ca194daaaa

happy5214/pywikibot-core,trishnaguha/pywikibot-core,VcamX/pywikibot-core,TridevGuha/pywikibot-core,npdoty/pywikibot,darthbhyrava/pywikibot-local,Darkdadaah/pywikibot-core,hasteur/g13bot_tools_new,valhallasw/pywikibot-core,magul/pywikibot-core,jayvdb/pywikibot-core,Darkdadaah/pywikibot-core,icyflame/batman,npdoty/pywikibot,smalyshev/pywikibot-core,jayvdb/pywikibot-core,hasteur/g13bot_tools_new,wikimedia/pywikibot-core,h4ck3rm1k3/pywikibot-core,PersianWikipedia/pywikibot-core,wikimedia/pywikibot-core,emijrp/pywikibot-core,hasteur/g13bot_tools_new,magul/pywikibot-core,h4ck3rm1k3/pywikibot-core,happy5214/pywikibot-core