CI: fix xheck_tag to be compatible with Amber

debian/check_release.py

@@ -5,6 +5,7 @@ Feed it the first changelog line, and then all available tags.
 """
 
 import re, sys
-tag = "v" + re.findall("\\((.*)\\)", input())[0]
+version = re.findall("\\((.*)\\)", input())[0]
+tag = 'v' + re.findall("([0-9]+\\.[0-9]+\\.[0-9]+).*", version)[0]
 if tag not in map(str.strip, sys.stdin.readlines()):
     raise Exception("Changelog's current version doesn't have a tag. Push the tag!")