Matlab gpufit_constrained wrong input check

[AlanMiranda]

I noticed that the inputs check in the matlab function "gpufit_constrained" is incorrect. When user_info is supplied, it is ignored because the condition "if nargin < 12" should be "if nargin < 11" in order to not initialize the user_info with an empty array. The rest of the nargin checks need to be corrected as well by substracting one to the nargin value check. After these corrections the function works correctly.

[jkfindeisen]

You're right. I fixed it in the last commit.