WebAPI: Change delimiter from string to char in preferences API

src/webui/api/appcontroller.cpp

@@ -165,7 +165,7 @@ void AppController::preferencesAction()
     data["ip_filter_enabled"] = session->isIPFilteringEnabled();
     data["ip_filter_path"] = Utils::Fs::toNativePath(session->IPFilterFile());
     data["ip_filter_trackers"] = session->isTrackerFilteringEnabled();
-    data["banned_IPs"] = session->bannedIPs().join("\n");
+    data["banned_IPs"] = session->bannedIPs().join('\n');
 
     // Speed
     // Global Rate Limits
@@ -231,7 +231,7 @@ void AppController::preferencesAction()
     QStringList authSubnetWhitelistStringList;
     for (const Utils::Net::Subnet &subnet : asConst(pref->getWebUiAuthSubnetWhitelist()))
         authSubnetWhitelistStringList << Utils::Net::subnetToString(subnet);
-    data["bypass_auth_subnet_whitelist"] = authSubnetWhitelistStringList.join("\n");
+    data["bypass_auth_subnet_whitelist"] = authSubnetWhitelistStringList.join('\n');
     data["web_ui_max_auth_fail_count"] = pref->getWebUIMaxAuthFailCount();
     data["web_ui_ban_duration"] = static_cast<int>(pref->getWebUIBanDuration().count());
     data["web_ui_session_timeout"] = pref->getWebUISessionTimeout();