Guard `ActionRecord::Base.exec_sql` against a readonly PostgreSQL cluster.

lib/freedom_patches/active_record_base.rb

@@ -5,6 +5,8 @@ class ActiveRecord::Base
     conn = ActiveRecord::Base.connection
     sql = ActiveRecord::Base.send(:sanitize_sql_array, args)
     conn.raw_connection.exec(sql)
+  rescue PG::ReadOnlySqlTransaction
+    Rails.logger.warn("WARN: PostgreSQL is in a readonly state. Performed a noop")
   end
 
   def self.exec_sql_row_count(*args)