Fix unsetting sticky mail ID

This was broken. However, we don't actually need to grab the
MailSetEntry, as we can simply extract the mail ID from the ID of the
entry.

src/mail-app/mail/view/MailViewModel.ts

@@ -10,7 +10,14 @@ import {
 	MailSetEntryTypeRef,
 	MailTypeRef,
 } from "../../../common/api/entities/tutanota/TypeRefs.js"
-import { elementIdPart, firstBiggerThanSecond, getElementId, isSameId, listIdPart } from "../../../common/api/common/utils/EntityUtils.js"
+import {
+	deconstructMailSetEntryId,
+	elementIdPart,
+	firstBiggerThanSecond,
+	getElementId,
+	isSameId,
+	listIdPart,
+} from "../../../common/api/common/utils/EntityUtils.js"
 import {
 	assertNotNull,
 	count,
@@ -503,8 +510,8 @@ export class MailViewModel {
 		for (const update of updates) {
 			if (isUpdateForTypeRef(MailSetEntryTypeRef, update) && isSameId(folder.entries, update.instanceListId)) {
 				if (update.operation === OperationType.DELETE && this.stickyMailId != null) {
-					const entry = listModel.getMailSetEntry(update.instanceId)
-					if (entry && isSameId(entry.mail, this.stickyMailId)) {
+					const { mailId } = deconstructMailSetEntryId(update.instanceId)
+					if (isSameId(mailId, elementIdPart(this.stickyMailId))) {
 						// Reset target before we dispatch event to the list so that our handler in onListStateChange() has up-to-date state.
 						this.stickyMailId = null
 					}