fix(mp): getSystemInfo safeAreaInsets.bottom question/133479

src/platforms/mp-weixin/helpers/system-info.js

@@ -19,7 +19,7 @@ function addSafeAreaInsets (result) {
       top: safeArea.top,
       left: safeArea.left,
       right: result.windowWidth - safeArea.right,
-      bottom: result.windowHeight - safeArea.bottom
+      bottom: Math.abs(result.screenHeight - safeArea.bottom)
     }
   }
 }