Compile protobuf files with duplicate imports.
For example, a.proto imports 'b.proto' and 'c.proto' and b.proto imports 'c.proto' as well, which is a valid case. But when try to compile a.proto, the compiler will complain about something like '{32,erl_lint,{redefine_record,c}}' and '{26,erl_lint,{duplicated_export,{decode_c,1}}}' followed by compilation failure.