fix phone regex in contact_us model

contact_us/models.py

@@ -44,9 +44,9 @@ class Request(AbstractStatusModel):
     email = models.EmailField(_('Email'))
     subject = models.CharField(_('Subject'), max_length=500)
     message = models.TextField(blank=True, null=True)
-    phone_regex = RegexValidator(regex=r'^\((+7)|8)?\d{10}$',
+    phone_regex = RegexValidator(regex=r'^((\+7)|8)?\d{10}$',
                                  message="Phone number must be entered in the format: '+99999999999'. Up to 12 digits allowed.")
-    phone = models.CharField(validators=[phone_regex], max_length=12, blank=True, null=True)
+    phone = models.CharField(validators=(phone_regex,), max_length=12, blank=True, null=True)
     status = models.SmallIntegerField(_('Status'), default=REQUEST_DEFAULT_STATUS, choices=REQUEST_STATUS_CHOICES)
 
     @property