"SVD did not converge bug fix

Sometimes I see "SVD did not converge" error in TT-tensor round. You can find particular TT-tensor here: https://www.dropbox.com/s/s0ipi3z7ct3klxw/svd_did_not_converge.mat
There is also a particular matrix that crush SVD. To reproduce the problem try this: 
>> load('svd_did_not_converge2.mat');
>> round(tt, 1e-2);
Error using svd
SVD did not converge.
>> [u, s, v] = svd(core0, 'econ');
Error using svd
SVD did not converge.
 
It turned out that svds is more reliable in this cases.