[LyX/2.3-staging] Avoid incorrect "Autocorrect Off" message

[Jean-Marc Lasgouttes]

commit 13c87041497743c56d590e9f54714168455d59b4
Author: Jean-Marc Lasgouttes <lasgout...@lyx.org>
Date:   Sun Feb 28 17:21:26 2016 +0100

    Avoid incorrect "Autocorrect Off" message

diff --git a/src/mathed/InsetMathNest.cpp b/src/mathed/InsetMathNest.cpp
index 493f529..9d90c19 100644
--- a/src/mathed/InsetMathNest.cpp
+++ b/src/mathed/InsetMathNest.cpp
@@ -715,8 +715,10 @@ void InsetMathNest::doDispatch(Cursor & cur, FuncRequest & 
cmd)
                cur.selHandle(select);
 
                // handle autocorrect:
-               cur.autocorrect() = false;
-               cur.message(_("Autocorrect Off ('!' to enter)"));
+               if (lyxrc.autocorrection_math && cur.autocorrect()) {
+                       cur.autocorrect() = false;
+                       cur.message(_("Autocorrect Off ('!' to enter)"));
+               }
 
                // go up/down
                bool up = act == LFUN_UP || act == LFUN_UP_SELECT;