patch 8.2.2418: color not changed if ModeMsg highlight is set in InsertEnter

Problem:    Color not changed if ModeMsg highlight is set in InsertEnter
            autocmd event. (Paul Swanson)
Solution:   Call highlight_changed() after triggering InsertEnter.
            (closes #7751)
diff --git a/src/edit.c b/src/edit.c
index 35e4bc2..9162fe6 100644
--- a/src/edit.c
+++ b/src/edit.c
@@ -196,6 +196,10 @@
 #endif
 	ins_apply_autocmds(EVENT_INSERTENTER);
 
+	// Check for changed highlighting, e.g. for ModeMsg.
+	if (need_highlight_changed)
+	    highlight_changed();
+
 	// Make sure the cursor didn't move.  Do call check_cursor_col() in
 	// case the text was modified.  Since Insert mode was not started yet
 	// a call to check_cursor_col() may move the cursor, especially with