fixes #956

Not tested, not sure if captive portal works with hidden ap, test please.
adds wm.setWiFiAPHidden(bool);

WiFiManager.cpp

@@ -371,20 +371,21 @@ bool WiFiManager::startAP(){
   }
 
   // start soft AP with password or anonymous
+  // default channel is 1 here and in esplib, @todo just change to default remove conditionals
   if (_apPassword != "") {
     if(channel>0){
-      ret = WiFi.softAP(_apName.c_str(), _apPassword.c_str(),channel);
+      ret = WiFi.softAP(_apName.c_str(), _apPassword.c_str(),channel,_apHidden);
     }  
     else{
-      ret = WiFi.softAP(_apName.c_str(), _apPassword.c_str());//password option
+      ret = WiFi.softAP(_apName.c_str(), _apPassword.c_str(),1,_apHidden);//password option
     }
   } else {
     DEBUG_WM(DEBUG_VERBOSE,F("AP has anonymous access!"));    
     if(channel>0){
-      ret = WiFi.softAP(_apName.c_str(),"",channel);
+      ret = WiFi.softAP(_apName.c_str(),"",channel,_apHidden);
     }  
     else{
-      ret = WiFi.softAP(_apName.c_str());
+      ret = WiFi.softAP(_apName.c_str(),"",1,_apHidden);
     }  
   }
 
@@ -2285,6 +2286,15 @@ void WiFiManager::setWiFiAPChannel(int32_t channel){
   _apChannel = channel;
 }
 
+/**
+ * set the soft ap hidden
+ * @param bool   wifi ap hidden, default is false
+ */
+void WiFiManager::setWiFiAPHidden(bool hidden){
+  _apHidden = hidden;
+}
+
+
 /**
  * toggle showing erase wifi config button on info page
  * @param boolean enabled

WiFiManager.h

@@ -257,7 +257,8 @@ class WiFiManager
     void          setShowInfoErase(boolean enabled);
     // set ap channel
     void          setWiFiAPChannel(int32_t channel);
-
+    // set ap hidden
+    void          setWiFiAPHidden(bool hidden); // default false
     // set custom menu
 
     // set custom menu items and order
@@ -339,6 +340,7 @@ class WiFiManager
     bool          _disableSTAConn         = true;  // disable sta when starting ap, if sta is not connected ( stability )
     bool          _channelSync            = false; // use same wifi sta channel when starting ap
     int32_t       _apChannel              = 0; // channel to use for ap
+    bool          _apHidden               = false; // store softap hidden value
 
     #ifdef ESP32
     static uint8_t _lastconxresulttmp; // tmp var for esp32 callback

examples/DEV/OnDemandConfigPortal/OnDemandConfigPortal.ino

@@ -175,6 +175,9 @@ void setup() {
   // set channel
   wm.setWiFiAPChannel(13);
   
+  // set AP hidden
+  // wm.setAPHidden(true);
+
   // set configrportal timeout
   wm.setConfigPortalTimeout(120);
   // wm.startConfigPortal("AutoConnectAP", "password");