fix(tabbar): revise safebottom scss (#1339)

src/packages/__VUE/tabbar/index.scss

@@ -21,7 +21,7 @@
   }
 
   &-safebottom {
-    margin-bottom: constant(safe-area-inset-bottom);
-    margin-bottom: env(safe-area-inset-bottom);
+    padding-bottom: constant(safe-area-inset-bottom);
+    padding-bottom: env(safe-area-inset-bottom);
   }
 }