tests: replace "naked except clause" to avoid check-code.py error
This is a part of preparation to apply checking with check-code.py on
code fragments embedded in *.t test scripts.
--- a/tests/test-acl.t Mon Feb 18 00:27:25 2019 +0900
+++ b/tests/test-acl.t Mon Feb 18 00:27:25 2019 +0900
@@ -38,7 +38,7 @@
> def fakegetusers(ui, group):
> try:
> return acl._getusersorig(ui, group)
- > except:
+ > except BaseException:
> return [b"fred", b"betty"]
> acl._getusersorig = acl._getusers
> acl._getusers = fakegetusers