phabricator: drop support for the legacy phabricator.auth.token config (BC)

The test for this broke in dc82ad1b7f77 when statistics started being tracked.
It wasn't noticed because none of the bots have the vcr module installed.  It
looks like the custom_patches argument should patch in the custom
httpconnection, and I can't figure out what is going on.

hgext/phabricator.py

@@ -165,38 +165,6 b' def urlencodenested(params):'
     process(b'', params)
     return util.urlreq.urlencode(flatparams)
 
-printed_token_warning = False
-
-def readlegacytoken(repo, url):
-    """Transitional support for old phabricator tokens.
-
-    Remove before the 4.7 release.
-    """
-    groups = {}
-    for key, val in repo.ui.configitems(b'phabricator.auth'):
-        if b'.' not in key:
-            repo.ui.warn(_(b"ignoring invalid [phabricator.auth] key '%s'\n")
-                         % key)
-            continue
-        group, setting = key.rsplit(b'.', 1)
-        groups.setdefault(group, {})[setting] = val
-
-    token = None
-    for group, auth in groups.iteritems():
-        if url != auth.get(b'url'):
-            continue
-        token = auth.get(b'token')
-        if token:
-            break
-
-    global printed_token_warning
-
-    if token and not printed_token_warning:
-        printed_token_warning = True
-        repo.ui.warn(_(b'phabricator.auth.token is deprecated - please '
-                       b'migrate to auth.phabtoken.\n'))
-    return token
-
 def readurltoken(repo):
     """return conduit url, token and make sure they exist
 
@@ -219,10 +187,8 b' def readurltoken(repo):'
         token = auth.get(b'phabtoken')
 
     if not token:
-        token = readlegacytoken(repo, url)
-        if not token:
-            raise error.Abort(_(b'Can\'t find conduit token associated to %s')
-                              % (url,))
+        raise error.Abort(_(b'Can\'t find conduit token associated to %s')
+                            % (url,))
 
     return url, token