[LyX/2.2.x] We don't need to crash here, but can try to continue in release mode.

[Richard Heck]

commit 928c7a3d6879a1612110c6715669629cf4f6ae4a
Author: Richard Heck <rgh...@lyx.org>
Date:   Thu Aug 4 21:57:13 2016 -0400

    We don't need to crash here, but can try to continue in release
    mode.
    
    (cherry picked from commit 0a603c5d0e370c8b9c9e0f5dfa024b6e500b2dd4)
---
 src/output_xhtml.cpp |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/src/output_xhtml.cpp b/src/output_xhtml.cpp
index 5a06b2f..6e4343c 100644
--- a/src/output_xhtml.cpp
+++ b/src/output_xhtml.cpp
@@ -344,7 +344,7 @@ bool XHTMLStream::closeFontTags()
                tag_stack_.pop_back();
                // this shouldn't happen, since then the font tags
                // weren't in any other tag.
-               LBUFERR(!tag_stack_.empty());
+               LASSERT(!tag_stack_.empty(), return true);
                curtag = tag_stack_.back();
        }