Leaving out `compress` causes assertion fail

[tdewolff]

When leaving out the compress option in the config file, the following error is thrown:

tilemaker: /usr/include/rapidjson/document.h:1051: rapidjson::GenericValue<Encoding, Allocator>& rapidjson::GenericValue<Encoding, Allocator>::operator[](const rapidjson::GenericValue<Encoding, SourceAllocator>&) [with SourceAllocator = rapidjson::MemoryPoolAllocator<>; Encoding = rapidjson::UTF8<>; Allocator = rapidjson::MemoryPoolAllocator<>]: Assertion `false' failed.
./run.sh: line 1: 2335482 Aborted                 (core dumped) tilemaker/tilemaker --config config.json --output navalsec.pmtiles --process process.lua