Removed gif 'support' from ImageData:encode (it never worked, DevIL doesn't support saving gifs)

src/modules/image/ImageData.cpp

@@ -168,7 +168,6 @@ StringMap<ImageData::Format, ImageData::FORMAT_MAX_ENUM>::Entry ImageData::forma
 {
 	{"tga", ImageData::FORMAT_TGA},
 	{"bmp", ImageData::FORMAT_BMP},
-	{"gif", ImageData::FORMAT_GIF},
 	{"jpg", ImageData::FORMAT_JPG},
 	{"png", ImageData::FORMAT_PNG},
 };

src/modules/image/ImageData.h

@@ -67,7 +67,6 @@ public:
 	{
 		FORMAT_TGA = 1,
 		FORMAT_BMP,
-		FORMAT_GIF,
 		FORMAT_JPG,
 		FORMAT_PNG,
 		FORMAT_MAX_ENUM

src/modules/image/devil/ImageData.cpp

@@ -194,9 +194,6 @@ void ImageData::encode(love::filesystem::File *f, ImageData::Format format)
 		case ImageData::FORMAT_TGA:
 			ilFormat = IL_TGA;
 			break;
-		case ImageData::FORMAT_GIF:
-			ilFormat = IL_GIF;
-			break;
 		case ImageData::FORMAT_JPG:
 			ilFormat = IL_JPG;
 			break;