Update error copy

app/controllers/merge_requests_controller.rb

@@ -116,7 +116,7 @@ private
 
   def validate_response
     if page == "absorbing_organisation" && merge_request_params[:absorbing_organisation_id].blank? && merge_request_params[:new_absorbing_organisation].blank?
-      @merge_request.errors.add(:absorbing_organisation_id, "Select an option")
+      @merge_request.errors.add(:absorbing_organisation_id, I18n.t("validations.merge_request.absorbing_organisation_blank"))
       render previous_template
     end
   end

config/locales/en.yml

@@ -512,6 +512,7 @@ en:
     merge_request:
       organisation_part_of_another_merge: "This organisation is part of another merge - select a different one"
       organisation_not_selected: "Select an organisation from the search list"
+      absorbing_organisation_blank: Select the organisation absorbing the others
 
   soft_validations:
     net_income:

spec/requests/merge_requests_controller_spec.rb

@@ -272,7 +272,7 @@ RSpec.describe MergeRequestsController, type: :request do
         it "renders the error" do
           request
 
-          expect(page).to have_content("Select an option")
+          expect(page).to have_content("Select the organisation absorbing the others")
         end
 
         it "does not update the request" do