Keep the default branch in the forked repositories (#2514)

src/main/scala/gitbucket/core/service/RepositoryCreationService.scala

@@ -180,12 +180,14 @@ trait RepositoryCreationService {
         Database() withTransaction { implicit session =>
           val originUserName = repository.repository.originUserName.getOrElse(repository.owner)
           val originRepositoryName = repository.repository.originRepositoryName.getOrElse(repository.name)
+          val originDefaultBranchName = repository.repository.defaultBranch
 
           insertRepository(
             repositoryName = repository.name,
             userName = accountName,
             description = repository.repository.description,
             isPrivate = repository.repository.isPrivate,
+            defaultBranch = originDefaultBranchName,
             originRepositoryName = Some(originRepositoryName),
             originUserName = Some(originUserName),
             parentRepositoryName = Some(repository.name),

src/main/scala/gitbucket/core/service/RepositoryService.scala

@@ -34,6 +34,7 @@ trait RepositoryService {
     userName: String,
     description: Option[String],
     isPrivate: Boolean,
+    defaultBranch: String = "master",
     originRepositoryName: Option[String] = None,
     originUserName: Option[String] = None,
     parentRepositoryName: Option[String] = None,
@@ -45,7 +46,7 @@ trait RepositoryService {
         repositoryName = repositoryName,
         isPrivate = isPrivate,
         description = description,
-        defaultBranch = "master",
+        defaultBranch = defaultBranch,
         registeredDate = currentDate,
         updatedDate = currentDate,
         lastActivityDate = currentDate,