localrepo: add some overlooked strkwargs love for py3

Differential Revision: https://phab.mercurial-scm.org/D3337

mercurial/localrepo.py

@@ -182,7 +182,7 b' class localcommandexecutor(object):'
         f = pycompat.futures.Future()
 
         try:
-            result = fn(**args)
+            result = fn(**pycompat.strkwargs(args))
         except Exception:
             pycompat.future_set_exception_info(f, sys.exc_info()[1:])
         else: