patch 8.2.2930: when a popup is visible a mouse move my restart Visual mode

Problem:    When a popup is visible a mouse move my restart Visual mode.
Solution:   Reset held_button when ending Visual mode. (closes #8318)
diff --git a/src/normal.c b/src/normal.c
index cb496dd..f8ec8e9 100644
--- a/src/normal.c
+++ b/src/normal.c
@@ -1380,6 +1380,7 @@
 #endif
 
     VIsual_active = FALSE;
+    reset_held_button();
     setmouse();
     mouse_dragging = 0;