Set WifiManager debug level. (#1014)

This allows for setting the WiFimanager debug level for more or less verbosity using the WM_DEBUG_LEVEL macro.
Valid values are:
        DEBUG_ERROR     = 0,
        DEBUG_NOTIFY    = 1, // default
        DEBUG_VERBOSE   = 2,
        DEBUG_DEV       = 3,
        DEBUG_MAX       = 4

main/main.ino

@@ -1100,6 +1100,8 @@ void setup_wifimanager(bool reset_settings) {
     }
   }
 
+  wifiManager.setDebugOutput(WM_DEBUG_LEVEL);
+
   // The extra parameters to be configured (can be either global or just in the setup)
   // After connecting, parameter.getValue() will get you the configured value
   // id/name placeholder/prompt default length