Use .jpg instead of .jpeg for image/jpeg

Revert "Resolve #795"

This reverts commit d6939b2913.

app/src/main/java/com/hippo/ehviewer/gallery/PageLoader2.java

@@ -28,7 +28,6 @@ public abstract class PageLoader2 extends PageLoader {
     // With dot
     public static final String[] SUPPORT_IMAGE_EXTENSIONS = {
             ".jpg", // Joint Photographic Experts Group
-            ".jpeg",
             ".png", // Portable Network Graphics
             ".gif", // Graphics Interchange Format
     };