Fail to configure if compression algorithm is unknown
Fail to configure if compression algorithm is unknown

Right now, using the option -Dcompression_default=LZ4
configures ROOT with ZLIB and only emits a status message,
which is less visible than a CMake warning. Therefore,
make the option case-insensitive as well to accept ZLIB,
LZ4, and LZMA as recognized values.

karies/root,root-mirror/root,olifre/root,karies/root,root-mirror/root,karies/root,root-mirror/root,root-mirror/root,olifre/root,karies/root,karies/root,olifre/root,root-mirror/root,root-mirror/root,olifre/root,olifre/root,olifre/root,olifre/root,karies/root,root-mirror/root,olifre/root,karies/root,karies/root,karies/root,olifre/root,karies/root,karies/root,root-mirror/root,olifre/root,root-mirror/root,root-mirror/root,olifre/root,root-mirror/root