No, for his time he wasn't that short. In fact, at 5ft 6" he was slightly taller than the average French soldier back then.
A large part of the myth about him being short comes from a) a mistranslation to English that listed him as bring 5ft 2"; b) the fact that by today's standard 5ft 6" is shorter than average; c) the fact that 'short man syndrome' is a convenient conclusion for his assertive / ambitious / power-hungry personality.
(There are plenty of other sources that also corroborate this.)