Unskip test for fallback scenario

with this commit the fallback to convert on interlaced
png images is not necessary anymore. But the server keeps it as
emergency fallback.

server/image.go

@@ -25,10 +25,8 @@ func ResizeImageFromGridfs(originalImage *mgo.GridFile, entry *Entry) (*image.Im
 	if imgErr != nil {
 		// reset pointer and re read the gridfs image
 		originalImage.Seek(0, 0)
-		// now it gets really hacky, since go does not support interlaced pngs
-		// http://code.google.com/p/go/issues/detail?id=6293
-		// we will call imagemagick in order to remove interlacing, and save the image
-		// if this fails as well, there must be something wrong
+
+		//if resizing with go tools fails, a fallback is implemented to use convett
 		unresizedImage, magickError := imageMagickFallback(originalImage)
 
 		if magickError == nil {
@@ -147,7 +145,7 @@ func EncodeImage(targetImage io.Writer, imageData image.Image, imageFormat strin
 	case "jpeg":
 		jpeg.Encode(targetImage, imageData, &jpeg.Options{jpeg.DefaultQuality})
 	case "png":
-	    encoder := png.Encoder{CompressionLevel: png.BestCompression}
+		encoder := png.Encoder{CompressionLevel: png.BestCompression}
 		encoder.Encode(targetImage, imageData)
 	case "gif":
 		gif.Encode(targetImage, imageData, &gif.Options{256, nil, nil})

server/image_test.go

@@ -189,7 +189,6 @@ func (s *ImageTestSuite) TestEncodeJpegImage(c *C) {
 
 // TestEncodePngImageInterlaced
 func (s *ImageTestSuite) TestEncodePngImageInterlaced(c *C) {
-	c.Skip("This test won't work as long as png does not support interlacing in go @see http://code.google.com/p/go/issues/detail?id=6293")
 	filename, _ := os.Getwd()
 	testPNG, err := os.Open(filename + "/../testdata/interlaced.png")
 	c.Assert(err, IsNil)