pspdecrypt doesn't extract gzip format to plaintext elf on PRXs

[zecoxao]

0x6 2 Compression Type 0x300-Plain, 0x200-KL4E, 0x100-2RLZ, 0x000-GZIP Little endian u16 & 0xF00
this flag can be found at PRX header, for some reason pspdecrypt handles everything properly except gzip formats, which it doesn't extract to plain elfs