helptext: fix sentence in extensions documentation
Differential Revision: https://phab.mercurial-scm.org/D9366
--- a/mercurial/helptext/internals/extensions.txt Mon Nov 23 11:47:06 2020 -0500
+++ b/mercurial/helptext/internals/extensions.txt Sun Nov 22 14:53:17 2020 -0500
@@ -175,7 +175,7 @@
Be aware that ``uisetup`` in NOT the function to configure a ``ui`` instance.
It's called only once per process, not per ``ui`` instance. Also, any changes
-to the ``ui`` may be discarded because the ``ui`` here temporarily loaded
+to the ``ui`` may be discarded because the ``ui`` here is a temporarily loaded
local configuration. So, it's generally wrong to do `ui.setconfig()` in
these callbacks. Notable exception is setting ``pre/post-<command>`` hooks
and extending ``ui.__class__``.