tests: update test-help to pass our import checker

tests/test-help.t

@@ -1516,8 +1516,8 b' Test omit indicating for help'
   > 
   > This paragraph is never omitted, too (for extension)
   > '''
-  > 
-  > from mercurial import help, commands
+  > from __future__ import absolute_import
+  > from mercurial import commands, help
   > testtopic = """This paragraph is never omitted (for topic).
   > 
   > .. container:: verbose