invite: fix email confirmation jwt

same issue as with auth.go, expiry was a string causing the library to
see it as expired.

api.go

@@ -418,7 +418,7 @@ func (app *appContext) newUser(req newUserDTO, confirmed bool) (f errorFunc, suc
 			"username":    req.Username,
 			"password":    req.Password,
 			"telegramPIN": req.TelegramPIN,
-			"exp":         strconv.FormatInt(time.Now().Add(time.Hour*12).Unix(), 10),
+			"exp":         time.Now().Add(time.Hour * 12).Unix(),
 			"type":        "confirmation",
 		}
 		tk := jwt.NewWithClaims(jwt.SigningMethodHS256, claims)

migrations.go

@@ -100,7 +100,7 @@ func migrateEmailStorage(app *appContext) error {
 		case map[string]interface{}:
 			return nil
 		default:
-			return fmt.Errorf("Email address was type %T, not string: \"%+v\"\n", addr, addr)
+			return fmt.Errorf("email address was type %T, not string: \"%+v\"\n", addr, addr)
 		}
 	}
 	config, err := ini.Load(app.configPath)

views.go

@@ -4,7 +4,6 @@ import (
 	"html/template"
 	"io/fs"
 	"net/http"
-	"strconv"
 	"strings"
 	"time"
 
@@ -249,7 +248,7 @@ func (app *appContext) InviteProxy(gc *gin.Context) {
 			return
 		}
 		claims, ok := token.Claims.(jwt.MapClaims)
-		expiryUnix, err := strconv.ParseInt(claims["exp"].(string), 10, 64)
+		expiryUnix := int64(claims["exp"].(float64))
 		if err != nil {
 			fail()
 			app.err.Printf("Failed to parse key expiry: %s", err)