Add the conceal patch from Vince Negri.
diff --git a/src/mbyte.c b/src/mbyte.c
index e627589..e4df00a 100644
--- a/src/mbyte.c
+++ b/src/mbyte.c
@@ -5222,7 +5222,7 @@
     /* If 'imdisable' is set, XIM is never active. */
     if (p_imdisable)
 	active = FALSE;
-#if !defined (FEAT_GUI_GTK)
+#if !defined(FEAT_GUI_GTK)
     else if (input_style & XIMPreeditPosition)
 	/* There is a problem in switching XIM off when preediting is used,
 	 * and it is not clear how this can be solved.  For now, keep XIM on