Address backend maintainer comments

app/controllers/import/base_controller.rb

@@ -77,10 +77,6 @@ class Import::BaseController < ApplicationController
     NamespaceSerializer.new.represent(namespaces)
   end
 
-  def already_added_project_names
-    @already_added_projects_names ||= already_added_projects.pluck(:import_source) # rubocop:disable CodeReuse/ActiveRecord
-  end
-
   def namespaces
     current_user.manageable_groups_with_routes
   end

app/controllers/import/bitbucket_controller.rb

@@ -80,7 +80,7 @@ class Import::BitbucketController < Import::BaseController
   # rubocop: disable CodeReuse/ActiveRecord
   override :importable_repos
   def importable_repos
-    already_added_projects_names = already_added_projects.pluck(:import_source)
+    already_added_projects_names = already_added_projects.map(&:import_source)
 
     bitbucket_repos.reject { |repo| (already_added_projects_names.include? repo.full_name) || !repo.valid? }
   end

app/controllers/import/bitbucket_server_controller.rb

@@ -49,8 +49,6 @@ class Import::BitbucketServerController < Import::BaseController
     else
       render json: { errors: _('This namespace has already been taken! Please choose another one.') }, status: :unprocessable_entity
     end
-  rescue BitbucketServer::Connection::ConnectionError => error
-    render json: { errors: _("Unable to connect to server: %{error}") % { error: error } }, status: :unprocessable_entity
   end
 
   def configure
@@ -91,7 +89,7 @@ class Import::BitbucketServerController < Import::BaseController
   def importable_repos
     # Use the import URL to filter beyond what BaseService#find_already_added_projects
     already_added_projects = filter_added_projects('bitbucket_server', bitbucket_repos.map(&:browse_url))
-    already_added_projects_names = already_added_projects.pluck(:import_source)
+    already_added_projects_names = already_added_projects.map(&:import_source)
 
     bitbucket_repos.reject { |repo| already_added_projects_names.include?(repo.browse_url) || !repo.valid? }
   end

app/controllers/import/fogbugz_controller.rb

@@ -90,7 +90,7 @@ class Import::FogbugzController < Import::BaseController
   def importable_repos
     repos = client.repos
 
-    already_added_projects_names = already_added_projects.pluck(:import_source)
+    already_added_projects_names = already_added_projects.map(&:import_source)
 
     repos.reject { |repo| already_added_projects_names.include? repo.name }
   end

app/controllers/import/gitlab_controller.rb

@@ -57,7 +57,7 @@ class Import::GitlabController < Import::BaseController
   def importable_repos
     repos = client.projects(starting_page: 1, page_limit: MAX_PROJECT_PAGES, per_page: PER_PAGE_PROJECTS)
 
-    already_added_projects_names = already_added_projects.pluck(:import_source)
+    already_added_projects_names = already_added_projects.map(&:import_source)
 
     repos.reject { |repo| already_added_projects_names.include? repo["path_with_namespace"] }
   end