FIX get readme api method

app/views/repositories/detail.json.jbuilder

@@ -1,6 +1,10 @@
 json.content @project.content
 json.website @project.website
-json.readme @result[:readme].merge(content: readme_render_decode64_content(@result[:readme]["content"], nil))
+if @result[:readme].blank?
+  json.readme nil!
+else
+  json.readme @result[:readme].merge(content: readme_render_decode64_content(@result[:readme]["content"], nil))
+end
 json.identifier render_identifier(@project)
 json.name @project.name
 json.project_id @project.id
@@ -48,7 +52,7 @@ if @result[:repo]
   json.private @result[:repo]['private']
 end
 json.license_name @project.license_name
-json.release_versions do 
+json.release_versions do
   json.list @result[:release].each do |release|
     forge_version = VersionRelease.find_by(version_gid: release["id"])
     json.id forge_version&.id
@@ -58,23 +62,23 @@ json.release_versions do
   end
   json.total_count @result[:release].size
 end
-json.branches do 
+json.branches do
   json.list @result[:branch].each do |branch|
     json.name branch["name"]
   end
   json.total_count @result[:branch].size
 end
-json.tags do 
-  json.list @result[:tag].each do |tag| 
+json.tags do
+  json.list @result[:tag].each do |tag|
     json.name tag["name"]
   end
-  json.total_count @result[:tag].size 
+  json.total_count @result[:tag].size
 end
-json.contributors do 
-  total_count = @result[:contributor].size 
+json.contributors do
+  total_count = @result[:contributor].size
   json.list @result[:contributor].each do |contributor|
     user = User.find_by(gitea_uid: contributor["id"])
-    if contributor["login"] == "root" 
+    if contributor["login"] == "root"
       total_count -= 1
       next
     end