Support default private when creating or migrating repository (#3239)

* support default private when creating or migrating repository

* fix fmt

* use string constants on repository default private in app.ini

* fix fmt

modules/setting/setting.go

@@ -70,6 +70,13 @@ type MarkupParser struct {
 	IsInputFile    bool
 }
 
+// enumerates all the policy repository creating
+const (
+	RepoCreatingLastUserVisibility = "last"
+	RepoCreatingPrivate            = "private"
+	RepoCreatingPublic             = "public"
+)
+
 // settings
 var (
 	// AppVer settings
@@ -180,6 +187,7 @@ var (
 	Repository = struct {
 		AnsiCharset            string
 		ForcePrivate           bool
+		DefaultPrivate         string
 		MaxCreationLimit       int
 		MirrorQueueLength      int
 		PullRequestQueueLength int
@@ -209,6 +217,7 @@ var (
 	}{
 		AnsiCharset:            "",
 		ForcePrivate:           false,
+		DefaultPrivate:         RepoCreatingLastUserVisibility,
 		MaxCreationLimit:       -1,
 		MirrorQueueLength:      1000,
 		PullRequestQueueLength: 1000,