Fix prepareFastGapFill bug related to KEGGMatrix

[nmendozam]

Rectifies KEGGMatrixLoad default value.

The bug was mentioned here.
When executing prepareFastGapFill this error happens:

Error using load
Unable to read file 'KEGGMatrix'. No such file or directory.

Error in generateSUXComp (line 49)
    load KEGGMatrix

Error in prepareFastGapFill (line 86)
MatricesSUX = generateSUXComp(consistModel,dictionary, filename,blackList,listCompartments);

In the comments says that the default values for KEGGMatrixLoad is 0 but in the code is 1 which makes it try to load something that hasn't been downloaded, jet.

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