adds disconnect method for users

non persistent disconnect

WiFiManager.cpp

@@ -1374,6 +1374,10 @@ bool WiFiManager::WiFi_Mode(WiFiMode_t m) {
 	return WiFi_Mode(m,false);
 }
 
+bool WiFiManager::disconnect(){
+  return WiFi_Disconnect();
+}
+
 // sta disconnect without persistent
 bool WiFiManager::WiFi_Disconnect() {
     if((WiFi.getMode() & WIFI_STA) != 0) {

WiFiManager.h

@@ -95,6 +95,7 @@ class WiFiManager
 
     void          resetSettings();
     void          reboot();
+    boolean       disconnect(); // non persistent disconnect
 
     //sets timeout before AP,webserver loop ends and exits even if there has been no setup.
     //useful for devices that failed to connect at some point and got stuck in a webserver loop