Make error optional in connection lost service check (#8937)

src/panels/developer-tools/service/developer-tools-service.ts

@@ -282,7 +282,7 @@ class HaPanelDevService extends LitElement {
     } catch (err) {
       const [domain, service] = this._serviceData.service.split(".", 2);
       if (
-        err.error.code === ERR_CONNECTION_LOST &&
+        err.error?.code === ERR_CONNECTION_LOST &&
         serviceCallWillDisconnect(domain, service)
       ) {
         return;

src/state/connection-mixin.ts

@@ -81,7 +81,7 @@ export const connectionMixin = <T extends Constructor<HassBaseEl>>(
             )) as Promise<ServiceCallResponse>;
           } catch (err) {
             if (
-              err.error.code === ERR_CONNECTION_LOST &&
+              err.error?.code === ERR_CONNECTION_LOST &&
               serviceCallWillDisconnect(domain, service)
             ) {
               throw err;