frontend: keep temp projects up to 2 years

Changing the limit in forms.py, updating max value to 720 days.

Fixes: fedora-copr#2927
Closes: fedora-copr#2931

frontend/coprs_frontend/coprs/forms.py

@@ -556,7 +556,7 @@ class CoprForm(BaseForm):
         "Delete after days",
         validators=[
             wtforms.validators.Optional(),
-            wtforms.validators.NumberRange(min=-1, max=60)
+            wtforms.validators.NumberRange(min=-1, max=720) #max allowable value for delete_after_days updated to 2 years
         ],
         filters=[(lambda x : -1 if x is None else x)])