remeasure fastscroller if thumbnail data changes

app/src/main/kotlin/com/simplemobiletools/gallery/adapters/DirectoryAdapter.kt

@@ -400,6 +400,7 @@ class DirectoryAdapter(activity: BaseSimpleActivity, var dirs: ArrayList<Directo
             dirs = newDirs.clone() as ArrayList<Directory>
             notifyDataSetChanged()
             finishActMode()
+            fastScroller?.measureRecyclerView()
         }
     }
 

app/src/main/kotlin/com/simplemobiletools/gallery/adapters/MediaAdapter.kt

@@ -260,6 +260,7 @@ class MediaAdapter(activity: BaseSimpleActivity, var media: MutableList<Medium>,
                 enableInstantLoad()
                 notifyDataSetChanged()
                 finishActMode()
+                fastScroller?.measureRecyclerView()
             }, 100L)
         }
     }