changelog: update version number generation to actual usage (#41851)

eobuilder/changelog.py

@@ -1,6 +1,7 @@
 import datetime
 import textwrap
 import os
+import re
 import sys
 
 import pytz
@@ -71,8 +72,8 @@ def changelog_from_git(project, version_suffix, path,
             continue
         version = name.lstrip('v').replace('-', '.')
         if is_pep0440:
-            # pep440 limit free-style version number after a +
-            version = version.replace('.g', '+g')
+            # use .postX+g form
+            version = re.sub('\.(\d+)\.g', r'.post\1+g', version)
         if i == 0:
             version += version_suffix
         if epoch: