The Russian Market has already lose the Chinese military market but bilateral ties are still strong and commercial dependant on each other are still important.
Russian authority may close one eye on military areas as commercial economic benefit outweight militaries industries. Plus Putin is very pro-Chinese. He knows keeping China as close allies is important to check USA.
He decided to risk the woes of Indian by approving RD-93 engines to China and continue selling of AL-31F engines.
For now Russia does not have to worry about India since India is still very much dependent upon Russian arms (Su-30 mki and Mig-29). Besides I am sure that banning RD-93 will anger the Chinese and Pakistanis since JF-17 is a ready to go aircraft. It is also possible that the withdraw of RD-93 (a bit of fantasizing here) might spur the development of the Chinese WS-13 and I really don't think that the Russians would want to see that happen (loosing huge market in China and possibly facing export competition).