Update pspm_display.m

[teddphil]

Fixes #744.

When a file is selected and I click on "done", the following error occurs (and the file selector remains frozen).

Cannot be replicated here... The function can run successfully.

When I close the file selector by clicking on the top-left cross, the following error message occurs

This is caused by the invalid usage of varargin at line 491--492 in pspm_display. That line of code is not really usable because varargin is not available inside load_Callback. This error has been fixed by removing these two lines.

Same error for pspm_review in develop branch, using models that were computed by the same version.

The issue is caused by unuqdated pspm_rev_glm . In pspm_review, it calls pspm_rev_glm by using three variables, but the second variable it calls is no longer needed in pspm_rev_glm. This has been updated in pspm_review and function description of pspm_rev_glm.