Remove duplicate supportsMultiLanguageSpellCheck()

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

src/vector/platform/WebPlatform.ts

@@ -46,14 +46,6 @@ export default class WebPlatform extends VectorBasePlatform {
         return 'Web Platform'; // no translation required: only used for analytics
     }
 
-    /**
-     * Return true if platform supports multi-language
-     * spell-checking, otherwise false.
-     */
-    supportsMultiLanguageSpellCheck(): boolean {
-        return false;
-    }
-
     /**
      * Returns true if the platform supports displaying
      * notifications, otherwise false.