But note that "noble" isn't really the right translation for "plemenit" (despite what Google translate might tell you) -- it's closer in meaning to "selfless" or "generous" (which you could argue are noble attributes, but "noble" has certain connotations in English that "plemenit" doesn't).
But to me it still doesn't sound right. I asked my mom (native Serbian speaker) and she said she's not heard of it as a proverb, and some Googling reveals that native Serbians are confused why foreigners seem to attribute it to us[1]. I also weirdly found a lot of questions on Quora and Yahoo answers asking for people to translate it to Serbian -- which explains why the proverb sounds slightly strange when read in Serbian. My guess is that this is actually some recent English proverb which someone decided to attribute to us (though it is neat that "zemlje" and "zvezda" do have a certain kind of rhyme).