WebRequests fixes
WebRequests fixes

- remove event listener after request to avoid mem leak
- increase connection limit
- limit request concurrency
- fixed rare worker crash and added exception handling

Nogrod/Oxide-2,MSylvia/Oxide,Nogrod/Oxide-2,Visagalis/Oxide,LaserHydra/Oxide,bawNg/Oxide,MSylvia/Oxide,Visagalis/Oxide,ApocDev/Oxide,ApocDev/Oxide,LaserHydra/Oxide,bawNg/Oxide