patch 9.0.1490: the ModeChanged event may be triggered too often

Problem:    The ModeChanged event may be triggered too often.
Solution:   Only trigger ModeChanged when no operator is pending.
            (closes #12298)

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1490,
 /**/
     1489,
 /**/