fullpacket: decompression only after init
fullpacket: decompression only after init

The buffer for the decompression (remote.comp_abstract) is initialised
in time when it is needed.  With this fix decompression is disabled when
the buffer (remote.comp_abstract) is not initialised.

Bug: http://trac.libssh2.org/ticket/200

libssh2/libssh2,libssh2/libssh2,libssh2/libssh2,libssh2/libssh2