tests: use absolute_import in hgweberror.py

tests/hgweberror.py

@@ -1,6 +1,10 b''
 # A dummy extension that installs an hgweb command that throws an Exception.
 
-from mercurial.hgweb import webcommands
+from __future__ import absolute_import
+
+from mercurial.hgweb import (
+    webcommands,
+)
 
 def raiseerror(web, req, tmpl):
     '''Dummy web command that raises an uncaught Exception.'''

tests/test-check-py3-compat.t

@@ -147,7 +147,6 b''
   tests/generate-working-copy-states.py requires print_function
   tests/get-with-headers.py requires print_function
   tests/heredoctest.py requires print_function
-  tests/hgweberror.py not using absolute_import
   tests/hypothesishelpers.py not using absolute_import
   tests/hypothesishelpers.py requires print_function
   tests/killdaemons.py not using absolute_import