Yeah. It is a persistent conspiracy theory about the embassy bombing that is still around until this day (in particular in China and Serbia, of course ...).

Here is an article from AP written ten years later, essentially saying that the Chinese based their J-20 stealth fighter on the pieces of the F-117 laying on the ground in Serbia:

https://www.theguardian.com/world/2011/jan/23/china-stealth-...

Chinese stealth fighter jet may use US technology

China may have bought parts of US F-117 Nighthawk shot down over Serbia in 1999, say experts