Etymologically, it just means "non-whores".

From Googling, I think it might possibly mean "non-whore" in an ironic, "the lady doth protest too much, methinks" kind of way. But I could be wrong about that.

PS. As Doomer said, the spelling is Ukrainian, not Russian. So I also did a Google search for the Russian spelling "небляди" and got SOME hits where the word appeared to be used in the sense of "non-slutty women." However, most of the hits were for a video that went totally viral on the Russian-speaking Internet -- in which a group of Israeli-Arab children are singing a song called Biladi, which means "My Homeland" in Arabic, but sounds like the Russian word that means "dirty-f*ckin-whore."