fix proton updater

proton-ge-updater.py

@@ -44,17 +44,24 @@ def dl_progress_old(count, bsize, size):
 
 with urlopen(Request(url, headers={'Accept': 'application/vnd.github.v3+json'})) as resp:
 	data = json.loads(resp.read())
+	release = None
 
-	try:
-		build = data['assets'][0]
-		release = {
-			'name': data['name'],
-			'size': build['size'],
-			'date:': build['created_at'],
-			'url': build['browser_download_url']
-		}
+	builds = data['assets']
 
-	except KeyError as e:
+    for build in builds:
+        if not build['browser_download_url'].endswith('.tar.gz')
+            continue
+
+    	release = {
+		'name': build['name'],
+    		'size': build['size'],
+    		'date:': build['created_at'],
+    		'url': build['browser_download_url']
+    	}
+
+        break
+
+	if not release:
 		print('Failed to get build info:', e)
 		sys.exit()