Fix #9189 - API Allow only specific Colums to be updated on Issue (#9539)

* dont insert "-1" in any case to issue.poster_id

* Make sure API cant override importand fields

* code format

* fix lint

* WIP test

* add missing poster_id

* fix test

* user.IsGhost handle nil

* CI.restart()

* make sure no -1 is realy added

* CI.restart()

* @lunny suggestion remove some not allowed fields

* seperate issue.LoadMilestone

* load milestone and return it on IssueEdit via API

* extend Test for TestAPIEditIssue

* fix fixtures

* declare allowedColumnsUpdateIssueByAPI only once

* Update Year

* no var just write id drecty into func cal

Co-authored-by: Lauris BH <lauris@nix.lv>

models/fixtures/issue.yml

@@ -108,4 +108,17 @@
   is_closed: false
   is_pull: true
   created_unix: 946684820
-  updated_unix: 978307180
+  updated_unix: 978307180
+
+-
+  id: 10
+  repo_id: 42
+  index: 1
+  poster_id: 500
+  name: issue from deleted account
+  content: content from deleted account
+  is_closed: false
+  is_pull: false
+  created_unix: 946684830
+  updated_unix: 999307200
+  deadline_unix: 1019307200