Use defined HTTP errors in WebHookService

This is a simple refactoring to reuse the list of exceptions defined
in `Gitlab::HTTP::HTTP_ERRORS`.

app/services/web_hook_service.rb

@@ -69,8 +69,7 @@ class WebHookService
       http_status: response.code,
       message: response.to_s
     }
-  rescue SocketError, OpenSSL::SSL::SSLError, Errno::ECONNRESET, Errno::ECONNREFUSED, Errno::EHOSTUNREACH,
-         Net::OpenTimeout, Net::ReadTimeout, Gitlab::HTTP::BlockedUrlError, Gitlab::HTTP::RedirectionTooDeep,
+  rescue *Gitlab::HTTP::HTTP_ERRORS,
          Gitlab::Json::LimitedEncoder::LimitExceeded, URI::InvalidURIError => e
     execution_duration = Gitlab::Metrics::System.monotonic_time - start_time
     log_execution(

spec/services/web_hook_service_spec.rb

@@ -128,11 +128,10 @@ RSpec.describe WebHookService do
     end
 
     it 'handles exceptions' do
-      exceptions = [
-        SocketError, OpenSSL::SSL::SSLError, Errno::ECONNRESET, Errno::ECONNREFUSED,
-        Errno::EHOSTUNREACH, Net::OpenTimeout, Net::ReadTimeout,
-        Gitlab::HTTP::BlockedUrlError, Gitlab::HTTP::RedirectionTooDeep
+      exceptions = Gitlab::HTTP::HTTP_ERRORS + [
+        Gitlab::Json::LimitedEncoder::LimitExceeded, URI::InvalidURIError
       ]
+
       exceptions.each do |exception_class|
         exception = exception_class.new('Exception message')
         project_hook.enable!