fix incrementing errors

.bumpversion.toml

@@ -12,7 +12,7 @@ parse = """(?x)
     )?                                  # smallpatch section is optional
     (?:
         (?P<pre_l>[a-zA-Z-]+)           # pre-release label
-        (?P<pre_n>[1-9]\\d*)            # pre-release version number
+        (?P<pre_n>0|[1-9]\\d*)            # pre-release version number
     )?                                  # pre-release section is optional
 """
 serialize = [