Update WiFiManager.cpp

tzapu#392
Increased size of parLength to 5 so the custom parameter length variable can be up to 9999 long.

Author: Derek123456

WiFiManager.cpp

@@ -485,7 +485,7 @@ void WiFiManager::handleWifi(boolean scan) {
   }
 
   page += FPSTR(HTTP_FORM_START);
-  char parLength[2];
+  char parLength[5];
   // add the extra parameters to the form
   for (int i = 0; i < _paramsCount; i++) {
     if (_params[i] == NULL) {
@@ -497,7 +497,7 @@ void WiFiManager::handleWifi(boolean scan) {
       pitem.replace("{i}", _params[i]->getID());
       pitem.replace("{n}", _params[i]->getID());
       pitem.replace("{p}", _params[i]->getPlaceholder());
-      snprintf(parLength, 2, "%d", _params[i]->getValueLength());
+      snprintf(parLength, 5, "%d", _params[i]->getValueLength());
       pitem.replace("{l}", parLength);
       pitem.replace("{v}", _params[i]->getValue());
       pitem.replace("{c}", _params[i]->getCustomHTML());