move photo panorama check on a background thread

app/src/main/kotlin/com/simplemobiletools/gallery/pro/fragments/PhotoFragment.kt

@@ -207,9 +207,12 @@ class PhotoFragment : ViewPagerFragment() {
         loadImage()
         initExtendedDetails()
         mWasInit = true
-        checkIfPanorama()
         updateInstantSwitchWidths()
 
+        ensureBackgroundThread {
+            checkIfPanorama()
+        }
+
         return mView
     }