network applet: keep visible networks under limit

When adding a network, if we add it to a menu index <
NUM_VISIBLE_NETWORKS, if we now have > NUM_VISIBLE_NETWORKS networks, we
need to push the last visible network to being the first network in the
"more" menu.  Otherwise, we could end up with too many visible networks.

When updating a network position, we first removed it from the menu.
When doing this, if its original menu index was < NUM_VISIBLE_NETWORKS,
then we need to bump the first network in the "more" menu to being the
last visible network.  We now do this by now calling the already
existing _accessPointRemoved() method which handles this case.
Otherwise, we could end up with too few visible networks.

files/usr/share/cinnamon/applets/network@cinnamon.org/applet.js

@@ -1385,8 +1385,7 @@ NMDeviceWireless.prototype = {
         }
 
         if (needsupdate) {
-            if (apObj.item)
-                apObj.item.destroy();
+            this._accessPointRemoved(device, accessPoint);
 
             if (pos != -1)
                 this._networks.splice(pos, 1);
@@ -1413,6 +1412,19 @@ NMDeviceWireless.prototype = {
 
             if (this._shouldShowConnectionList()) {
                 this._createNetworkItem(apObj, menuPos);
+                if (menuPos < NUM_VISIBLE_NETWORKS && this._networks.length > NUM_VISIBLE_NETWORKS) {
+                    for (; menuPos < NUM_VISIBLE_NETWORKS; ++pos) {
+                        if (this._networks[pos] != this._activeNetwork)
+                            menuPos++;
+                    }
+                    let item = this._networks[pos].item;
+                    if (item && item._apObj) {
+                        item.destroy();
+                        item._apObj.item = null;
+
+                        this._createNetworkItem(item._apObj, NUM_VISIBLE_NETWORKS);
+                    }
+                }
             }
         }
     },