Added clearAPList method to WiFiMulti (#1848)

Fixes #1846

libraries/WiFi/src/WiFiMulti.cpp

@@ -58,6 +58,15 @@ bool WiFiMulti::addAP(const char *ssid, const char *pass) {
     return true;
 }
 
+void WiFiMulti::clearAPList() {
+    while (!_list.empty()) {
+        struct _AP ap = _list.front();
+        _list.pop_front();
+        free(ap.ssid);
+        free(ap.pass);
+    }
+}
+
 uint8_t WiFiMulti::run(uint32_t to) {
     struct _scanAP {
         char *ssid;

libraries/WiFi/src/WiFiMulti.h

@@ -32,6 +32,8 @@ public:
 
     bool addAP(const char *ssid, const char *pass = nullptr);
 
+    void clearAPList();
+
     uint8_t run(uint32_t to = 10000);
 
 private: