Add ability to revert to non-hyphenated user IDs

The first 10.7.0 build i tried used hyphens, but a later one didn't.
emails.json can now be converted between the two forms depending on what
the server uses.

storage.go

@@ -192,10 +192,34 @@ func storeJSON(path string, obj interface{}) error {
 	return err
 }
 
-// JF 10.7.0 added hyphens to user IDs like this and we need to upgrade email storage to match it:
-// [8 chars]-[4]-[4]-[4]-[12]
-// This seems consistent, but we'll grab IDs from jellyfin just in case theres some variation.
-func (app *appContext) upgradeEmailStorage(old map[string]interface{}) (map[string]interface{}, int, error) {
+// One build of JF 10.7.0 hyphenated to user IDs like this and we need to upgrade email storage to match it:
+// One build of JF 10.7.0 hyphenated user IDs while another one later didn't. These functions will hyphenate/de-hyphenate email storage.
+
+func hyphenate(userID string) string {
+	if userID[8] == '-' {
+		return userID
+	}
+	return userID[:8] + "-" + userID[8:12] + "-" + userID[12:16] + "-" + userID[16:20] + "-" + userID[20:]
+}
+
+func (app *appContext) deHyphenateEmailStorage(old map[string]interface{}) (map[string]interface{}, int, error) {
+	jfUsers, status, err := app.jf.GetUsers(false)
+	if status != 200 || err != nil {
+		return nil, status, err
+	}
+	newEmails := map[string]interface{}{}
+	for _, user := range jfUsers {
+		unHyphenated := user["Id"].(string)
+		hyphenated := hyphenate(unHyphenated)
+		email, ok := old[hyphenated]
+		if ok {
+			newEmails[unHyphenated] = email
+		}
+	}
+	return newEmails, status, err
+}
+
+func (app *appContext) hyphenateEmailStorage(old map[string]interface{}) (map[string]interface{}, int, error) {
 	jfUsers, status, err := app.jf.GetUsers(false)
 	if status != 200 || err != nil {
 		return nil, status, err