Tighten a bit asp and iis detection (#2260)
Tighten a bit asp and iis detection (#2260)

- The x-powered-by header is trustworthy for ASP
- The `server` header for IIS always starts with `IIS`
WPO-Foundation/Wappalyzer,AliasIO/wappalyzer,WPO-Foundation/Wappalyzer,AliasIO/wappalyzer,WPO-Foundation/Wappalyzer