tweak tick0 in kavrayskiy7 mock to match previous behavior

Author: etpinard

test/image/baselines/geo_kavrayskiy7.png

@@ -72,10 +72,8 @@
             },
             "lataxis": {
                 "showgrid": true,
-                "range": [
-                    -75,
-                    85
-                ],
+                "range": [ -75, 85 ],
+                "tick0": 0,
                 "gridwidth": 2,
                 "gridcolor": "black"
             }