Fix progressive jpeg encoding.

Author: reinink

src/Manipulators/Encode.php

@@ -20,17 +20,17 @@ public function run(Image $image)
         $format = $this->getFormat($image);
         $quality = $this->getQuality();
 
-        if ($format === 'pjpg') {
-            $image->interlace();
-            $format = 'jpg';
-        }
-
-        if ($format === 'jpg') {
+        if (in_array($format, ['jpg', 'pjpg'], true)) {
             $image = $image->getDriver()
                            ->newImage($image->width(), $image->height(), '#fff')
                            ->insert($image, 'top-left', 0, 0);
         }
 
+        if ($format === 'pjpg') {
+            $image->interlace();
+            $format = 'jpg';
+        }
+
         return $image->encode($format, $quality);
     }