Device Registration for Notifications Fails – ECONNREFUSED

### ⚠️ Before posting ⚠️

- [x] This is a **bug**, not a question or an enhancement.
- [x] I've [searched for similar issues](https://github.com/nextcloud/android/issues) and didn't find a duplicate.
- [x] I've written a clear and descriptive title for this issue, not just "Bug" or "Crash".
- [x] I agree to follow Nextcloud's [Code of Conduct](https://nextcloud.com/contribute/code-of-conduct/).

### Expected behaviour

Error should not appear or should handle correctly

### Actual behaviour

Error appear in the log

### Android version

15

### Device brand and model

Android Emulator

### Stock or custom OS?

Stock

### Nextcloud android app version

3.31.0

### Nextcloud server version

31.0.0

### Log

```
RegisterAc...yOperation com.nextcloud.client E Exception while registering device for notifications
java.net.ConnectException: failed to connect to push-notifications.nextcloud.com/2a01:4f9:2b:29dc::153 (port 443) from /:: (port 48483): connect failed: ECONNREFUSED (Connection refused)
at libcore.io.IoBridge.connect(IoBridge.java:187)
at java.net.PlainSocketImpl.socketConnect(PlainSocketImpl.java:142)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:390)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:230)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:212)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:436)
at java.net.Socket.connect(Socket.java:646)
at com.google.android.gms.org.conscrypt.AbstractConscryptSocket.connect(:com.google.android.gms@250934035@25.09.34 (260400-738842635):6)
at com.owncloud.android.lib.common.network.AdvancedSslSocketFactory.createSocket(AdvancedSslSocketFactory.java:169)
at org.apache.commons.httpclient.HttpConnection.open(HttpConnection.java:707)
at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:387)
at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:171)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:323)
at com.owncloud.android.lib.resources.notifications.RegisterAccountDeviceForProxyOperation.run(RegisterAccountDeviceForProxyOperation.java:64)
at com.owncloud.android.utils.PushUtils.pushRegistrationToServer(PushUtils.java:218)
at com.owncloud.android.ui.activity.FileDisplayActivity.onMessageEvent(FileDisplayActivity.java:2475)
at java.lang.reflect.Method.invoke(Native Method)
at org.greenrobot.eventbus.EventBus.invokeSubscriber(EventBus.java:517)
at org.greenrobot.eventbus.EventBus.invokeSubscriber(EventBus.java:511)
at org.greenrobot.eventbus.BackgroundPoster.run(BackgroundPoster.java:64)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:644)
at java.lang.Thread.run(Thread.java:1012)
Caused by: android.system.ErrnoException: connect failed: ECONNREFUSED (Connection refused)
at libcore.io.Linux.connect(Native Method)
at libcore.io.ForwardingOs.connect(ForwardingOs.java:201)
at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:158)
at libcore.io.ForwardingOs.connect(ForwardingOs.java:201)
at libcore.io.IoBridge.connectErrno(IoBridge.java:201)
at libcore.io.IoBridge.connect(IoBridge.java:179)
at java.net.PlainSocketImpl.socketConnect(PlainSocketImpl.java:142)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:390)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:230)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:212)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:436)
at java.net.Socket.connect(Socket.java:646)
at com.google.android.gms.org.conscrypt.AbstractConscryptSocket.connect(:com.google.android.gms@250934035@25.09.34 (260400-738842635):6)
at com.owncloud.android.lib.common.network.AdvancedSslSocketFactory.createSocket(AdvancedSslSocketFactory.java:169)
at org.apache.commons.httpclient.HttpConnection.open(HttpConnection.java:707)
at org.apache.commons.httpclient.HttpMethodDirector.executeWithRetry(HttpMethodDirector.java:387)
at org.apache.commons.httpclient.HttpMethodDirector.executeMethod(HttpMethodDirector.java:171)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:397)
at org.apache.commons.httpclient.HttpClient.executeMethod(HttpClient.java:323)
at com.owncloud.android.lib.resources.notifications.RegisterAccountDeviceForProxyOperation.run(RegisterAccountDeviceForProxyOperation.java:64)
at com.owncloud.android.utils.PushUtils.pushRegistrationToServer(PushUtils.java:218)
at com.owncloud.android.ui.activity.FileDisplayActivity.onMessageEvent(FileDisplayActivity.java:2475)
at java.lang.reflect.Method.invoke(Native Method)
at org.greenrobot.eventbus.EventBus.invokeSubscriber(EventBus.java:517)
at org.greenrobot.eventbus.EventBus.invokeSubscriber(EventBus.java:511)
at org.greenrobot.eventbus.BackgroundPoster.run(BackgroundPoster.java:64)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:644)
at java.lang.Thread.run(Thread.java:1012)

```