【fix】修复mapboxgl themelayer 关闭事件报错、失败的问题 review by luoxiao

Author: songyumeng

src/mapboxgl/overlay/theme/ThemeLayer.js

@@ -372,7 +372,7 @@ export class Theme {
     off(event, callback, context) { // eslint-disable-line no-unused-vars
         var me = this;
         if (me.renderer) {
-            me.renderer.off(event, callback);
+            me.renderer.un(event, callback);
         } else {
             this.map.off(event, callback);
         }

test/mapboxgl/overlay/RangeThemeLayerSpec.js

@@ -431,6 +431,8 @@ describe('mapboxgl_RangeThemeLayer', () => {
                         expect(1).not.toBeNull();
                     }
                     themeLayer.clear();
+                    themeLayer.on('mousemove',function(){});
+                    themeLayer.off('mousemove')
                     done();
                 }
             }