Make it possible to retry build that was canceled

app/models/ci/build.rb

@@ -135,7 +135,7 @@ module Ci
 
     def retryable?
       project.builds_enabled? && commands.present? &&
-        (success? || failed?)
+        (success? || failed? || canceled?)
     end
 
     def retried?

spec/models/build_spec.rb

@@ -918,6 +918,14 @@ describe Ci::Build, models: true do
 
         it { is_expected.to be_retryable }
       end
+
+      context 'when build is canceled' do
+        before do
+          build.cancel!
+        end
+
+        it { is_expected.to be_retryable }
+      end
     end
 
     context 'when build is not retryable' do