No, there's not really any truth to it. As I explained in this previous answer:

What did a traditional French maid's outfit look like?

It's difficult to determine exactly when black became the required uniform color for maids. Even as late as 1859, "Mrs. Motherly's" The Servant's Behaviour Book; or, Hints on Manners and Dress for Maid Servants in Small Households spent pages explaining to girls in domestic service that it was imperative to wear dresses that were neat and presentable as well as hard-wearing and practical, but did not tell them to dress in black. In fact, the author recommended that lighter-colored cotton dresses be worn in the morning as soon as a maid was good enough at her duties not to dirty them, and Cassel's Household Guide (1869 and 1881 editions) told lady's maids that they could wear whatever they wanted in general (and encouraged them to be as fashionable as possible - in general, lower-level maidservants were encouraged to conform enough to fashionable styles so as not to appear dowdy or poorly-paid, but to keep away from such excesses as would lead them to spend too much time on their own clothing or give rise to telling-the-mistress-from-the-maid syndrome), but should only wear their mistress's cast-offs if they were dark-colored or black, in order to maintain a distinction between them. It's not until closer to the end of the century that handbooks like Domestic Economy, by Dr. Arthur Newsholme and Margaret Scott (1895) start to say that a maid waiting at the table must be dressed in black - but it's possible that housemaids were being required to wear black in the 1870s/1880s, and the handbooks simply weren't noting this because it was presumed to be obvious. We can certainly say that a black dress with a white apron an cap was the uniform by 1900, however.

The particular outfit worn in the movie is a later invention, because at the time the movie was set, there wasn't really a concept of a maid's uniform, per se. Free maids either wore their own simple dresses, or, if they were slaves or in a big household, they made dresses out of fabric that was given to them, and as this could be one specific fabric, it would come off as a uniform.

The French maid was often seen in an erotic light in the nineteenth century Anglosphere - French people as a whole were often sexualized, and French women were portrayed as languid, louche seducers and flirtatious coquettes. But for the origin of the specific stereotype of the sexy French housemaid in the specific short black dress and frilly white apron, we'll need /u/annalspornographie, as I bet he knows!

In the movie "Django Unchained", American house servants are pictured wearing French maid uniforms. Is there any historical truth to this?

Also, I'm sorry but I have to correct you. The women wearing these uniforms were people who were enslaved, not servants. Servants are people who have some level of both economic and social freedom, something enslaved people, especially in America during the 1850s, most especially lacked. To call them that, is to incorrectly represent their circumstances.

Both academic and public historians over the last few decades have been very quick to focus on using on using this right terminology to make sure that we properly represent the past. Many have gone on to argue that we should even refer to people as "enslaved" rather than simply "slaves", since the word 'slave' is a noun, which reduces a person to their socio-economic status, rather than 'enslaved' which is an adjective, which describes one part of this person's life. Even though people who were enslaved lived very difficult lives that were filled with suffering, they also had personal lives. They married, went to church, told oral histories, cooked, baked, sowed for their families and did many other things rather than simply being a 'slave.'