gst/gstregistrybinary.*: Don't write and check a CRC for the binary registry file. It's guaranteed that the registry ...

Original commit message from CVS:
* gst/gstregistrybinary.c: (gst_registry_binary_write_chunk),
(gst_registry_binary_initialize_magic),
(gst_registry_binary_write_cache),
(gst_registry_binary_check_magic):
* gst/gstregistrybinary.h:
Don't write and check a CRC for the binary registry file. It's
guaranteed that the registry is completely written (it's first written
to a temporary file and then moved) and if the registry was corrupted
by some hardware failure we would have bigger problems.
Bump binary registry version to 0.10.21.1 for this as it's an
incompatible change and to ensure that the registry gets rebuild
after the update.
This saves some milliseconds for reading/writing the registry.
Fixes bug #560399.