axes_test: remove redundant setting of minexponent

Author: ignamv

test/jasmine/tests/axes_test.js

@@ -2722,9 +2722,6 @@ describe('Test axes', function() {
 
     describe('calcTicks and tickText', function() {
         function mockCalc(ax) {
-            if(ax.minexponent === undefined) {
-                ax.minexponent = 3;
-            }
             ax.tickfont = {};
             Axes.setConvert(ax, {separators: '.,', _extraFormat: {
                 year: '%Y',