fetch: remove shorthand of --edit colliding against -e/-ssh in remoteopts (BC)

Before this patch, -e/--edit and -e/--ssh of fetch command collide
against each other. This causes that -e is treated as shorthand of
--edit but doesn't work as same as --edit. Therefore, -e works as
neither --edit nor --ssh, in practice.

This issue was introduced at 595a69a01129 (or 1.0), which renamed
-f/--force-editor to -e/--edit. At that point, -e was already used as
shorthand of --ssh.

After this patch, -e is treated as shorthand of --ssh.

This patch is marked as "(BC)", because -e as shorthand of --edit in
existing scripts causes failure (or unexpected result) after this
patch. This impact should be less enough, because --edit mainly
focuses on interactive use.

BTW, test-duplicateoptions.py (since 7d171c05a631 or 1.9) can't detect
this kind of issues as expected, because direct invocation of
extensions.loadall() doesn't involve registration of commands defined
in extensions (this issue is fixed in subsequent patch).

hgext/fetch.py

@@ -35,7 +35,7 testedwith = 'ships-with-hg-core'
 @command('fetch',
     [('r', 'rev', [],
      _('a specific revision you would like to pull'), _('REV')),
-    ('e', 'edit', None, _('invoke editor on commit messages')),
+    ('', 'edit', None, _('invoke editor on commit messages')),
     ('', 'force-editor', None, _('edit commit message (DEPRECATED)')),
     ('', 'switch-parent', None, _('switch parents when merging')),
     ] + cmdutil.commitopts + cmdutil.commitopts2 + cmdutil.remoteopts,