update crate to 0.51.6 stable

library/crate

@@ -7,8 +7,8 @@
 
 # see also https://crate.io
 
-latest: git://github.com/crate/docker-crate@5f5e55b3f83885e1acd40bf38902883d72732eca
-0.49: git://github.com/crate/docker-crate@8762d54054d9ed9d76a3bba0f9e6fa38acd34c2a
-0.49.6: git://github.com/crate/docker-crate@8762d54054d9ed9d76a3bba0f9e6fa38acd34c2a
+latest: git://github.com/crate/docker-crate@4a209c54bd664b0b0dd762ce533ac886b35d38c5
 0.50: git://github.com/crate/docker-crate@5f5e55b3f83885e1acd40bf38902883d72732eca
 0.50.8: git://github.com/crate/docker-crate@5f5e55b3f83885e1acd40bf38902883d72732eca
+0.51: git://github.com/crate/docker-crate@4a209c54bd664b0b0dd762ce533ac886b35d38c5
+0.51.6: git://github.com/crate/docker-crate@4a209c54bd664b0b0dd762ce533ac886b35d38c5