MOPPAND-1699 Fix for empty Proxy port crash (check connectivity).

Author: ambrose40

app/src/main/kotlin/ee/ria/DigiDoc/fragment/screen/ProxyServicesSettingsScreen.kt

@@ -743,10 +743,16 @@ fun ProxyServicesSettingsScreen(
                 verticalAlignment = Alignment.CenterVertically,
             ) {
                 TextButton(onClick = {
+                    val proxyPort =
+                        if (proxyPort.text == "") {
+                            0
+                        } else {
+                            proxyPort.text.toInt()
+                        }
                     sharedSettingsViewModel.checkConnection(
                         ManualProxy(
                             host = proxyHost.text,
-                            port = proxyPort.text.toInt(),
+                            port = proxyPort,
                             username = proxyUsername.text,
                             password = proxyPassword.text,
                         ),