Increase specificity of [url][img] capture regex in BBCode::getAttachedData

- Prevents it from over capturing when there's a [url] tag before the image

src/Content/Text/BBCode.php

@@ -273,7 +273,7 @@ class BBCode
 			$body = preg_replace("/\[img\=(.*?)\](.*?)\[\/img\]/ism", '[img]$1[/img]', $body);
 			$post['text'] = $body;
 
-			if (preg_match_all("(\[url=(.*?)\]\s*\[img\](.*?)\[\/img\]\s*\[\/url\])ism", $body, $pictures, PREG_SET_ORDER)) {
+			if (preg_match_all("#\[url=([^\]]+?)\]\s*\[img\]([^\[]+?)\[/img\]\s*\[/url\]#ism", $body, $pictures, PREG_SET_ORDER)) {
 				if ((count($pictures) == 1) && !$has_title) {
 					if (!empty($item['object-type']) && ($item['object-type'] == Activity\ObjectType::IMAGE)) {
 						// Replace the preview picture with the real picture