Update fails at "Fetching installer data." with certain games

I've ran into an issue when updating certain games, different from #15. So far i've encountered this when updating BattleTech, Tower of Time and SOMA.
mike@bigrig:~/GOG Games/BATTLETECH$ RUST_BACKTRACE=1 wyvern -vvvv update
 INFO 2019-03-19T19:17:27Z: wyvern: Path not specified. Using current dir
 INFO 2019-03-19T19:17:27Z: wyvern: Updating game
 INFO 2019-03-19T19:17:27Z: wyvern::games::update: Reading in gameinfo file
 INFO 2019-03-19T19:17:27Z: wyvern::games::update: Parsing gameinfo
 INFO 2019-03-19T19:17:27Z: wyvern::config: Getting name from gameinfo
 INFO 2019-03-19T19:17:27Z: wyvern::config: Getting version string from gameinfo
 INFO 2019-03-19T19:17:27Z: wyvern::games::update: Searching GOG products for BATTLETECH
 INFO 2019-03-19T19:17:28Z: wyvern::games::update: Fetching the GameDetails for first result of search
 INFO 2019-03-19T19:17:29Z: wyvern::games::update: Getting game's linux downloads
 INFO 2019-03-19T19:17:29Z: wyvern::games::update: Fetching installer data.
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Custom { kind: UnexpectedEof, error: StringError("failed to fill whole buffer") }', src/libcore/result.rs:997:5
stack backtrace:
   0: std::sys::unix::backtrace::tracing::imp::unwind_backtrace
             at src/libstd/sys/unix/backtrace/tracing/gcc_s.rs:39
   1: std::sys_common::backtrace::_print
             at src/libstd/sys_common/backtrace.rs:70
   2: std::panicking::default_hook::{{closure}}
             at src/libstd/sys_common/backtrace.rs:58
             at src/libstd/panicking.rs:200
   3: std::panicking::default_hook
             at src/libstd/panicking.rs:215
   4: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:478
   5: std::panicking::continue_panic_fmt
             at src/libstd/panicking.rs:385
   6: rust_begin_unwind
             at src/libstd/panicking.rs:312
   7: core::panicking::panic_fmt
             at src/libcore/panicking.rs:85
   8: core::result::unwrap_failed
             at /rustc/2aa4c46cfdd726e97360c2734835aa3515e8c858/src/libcore/macros.rs:16
   9: <core::result::Result<T, E>>::unwrap
             at /rustc/2aa4c46cfdd726e97360c2734835aa3515e8c858/src/libcore/result.rs:798
  10: gog::extract::CDEntry::from_reader
             at /home/mike/.cargo/git/checkouts/gog-rs-3c06ac510bb5cd16/0d2a926/src/extract.rs:175
  11: gog::Gog::extract_data
             at /home/mike/.cargo/git/checkouts/gog-rs-3c06ac510bb5cd16/0d2a926/src/lib.rs:752
  12: wyvern::games::update::update
             at src/games.rs:38
  13: wyvern::parse_args
             at src/main.rs:397
  14: wyvern::main
             at src/main.rs:89
  15: std::rt::lang_start::{{closure}}
             at /rustc/2aa4c46cfdd726e97360c2734835aa3515e8c858/src/libstd/rt.rs:64
  16: std::panicking::try::do_call
             at src/libstd/rt.rs:49
             at src/libstd/panicking.rs:297
  17: __rust_maybe_catch_panic
             at src/libpanic_unwind/lib.rs:92
  18: std::rt::lang_start_internal
             at src/libstd/panicking.rs:276
             at src/libstd/panic.rs:388
             at src/libstd/rt.rs:48
  19: std::rt::lang_start
             at /rustc/2aa4c46cfdd726e97360c2734835aa3515e8c858/src/libstd/rt.rs:64
  20: main
  21: __libc_start_main
  22: _start
nicohman / wyvern

Update fails at "Fetching installer data." with certain games #16
