fix OC_Image: Prevent E_WARNING from getimagesize*

Signed-off-by: Marcel Klehr <mklehr@gmx.net>

Author: marcelklehr

lib/private/legacy/OC_Image.php

@@ -598,7 +598,7 @@ private function checkImageMemory($width, $height) {
 	 * @return bool true if allocating is allowed, false otherwise
 	 */
 	private function checkImageSize($path) {
-		$size = getimagesize($path);
+		$size = @getimagesize($path);
 		if (!$size) {
 			return true;
 		}
@@ -619,7 +619,7 @@ private function checkImageSize($path) {
 	 * @return bool true if allocating is allowed, false otherwise
 	 */
 	private function checkImageDataSize($data) {
-		$size = getimagesizefromstring($data);
+		$size = @getimagesizefromstring($data);
 		if (!$size) {
 			return true;
 		}