added filter:image.size

fix uploading of gifs if imagemagick plugin is installed but no image
upload plugins are present.

src/controllers/uploads.js

@@ -83,7 +83,7 @@ function resizeImage(fileObj, callback) {
 		function(next) {
 			fullPath = path.join(nconf.get('base_dir'), nconf.get('upload_path'), '..', fileObj.url);
 
-			image.load(fullPath, next);
+			image.size(fullPath, next);
 		},
 		function (imageData, next) {
 			if (imageData.width < parseInt(meta.config.maximumImageWidth, 10) || 760) {