Saving new milestone ignores due date

[modmew8]

• Gitea version (or commit ref): 1.4.0
• Git version: 2.14.3
• Operating system: Ubuntu Server 16.04
• Database (use [x]):
  • PostgreSQL
  • MySQL
  • MSSQL
  • SQLite
• Can you reproduce the bug at https://try.gitea.io:
  • Yes (provide example URL)
  • No
  • Not relevant
• Log gist:

Description

The due date field on creating a new milestone is being ignored. Either leaving it blank or selecting a date, same as inserting a date by typing it results in a milestone that is due today.

Steps to reproduce

1. create a new milestone
2. leave the due date blank / set any due date
3. click save
4. due date is being set to the current day, ignoring the due date specified before