amend: support "history-editing-backup" config option
Now, amend is in the list of those history editing commands
which support `history-editing-backup` config option.
If you don't want to store any backup then just use this config.
[ui]
hisotry-editing-backup = False
Current status of list of history editing commands which support
this config:
1. histedit
2. rebase
3. amend
Differential Revision: https://phab.mercurial-scm.org/D3968
$ rm -rf a
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Am0
adding a
$ hg tag t1 # 1
$ hg tag --remove t1 # 2
$ hg co 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tag -f -r0 t1
$ hg tags
tip 3:a49829c4fc11
t1 0:f7b1eb17ad24
$ cd ..