Update percona to 5.7.18-16-1.jessie

See docker-library/percona#47

library/percona

@@ -5,13 +5,13 @@ Maintainers: Tianon Gravi <[email protected]> (@tianon),
 GitRepo: https://github.com/docker-library/percona.git
 
 Tags: 5.7.18, 5.7, 5, latest
-GitCommit: 6c952606d78b4b0e1041ad91514aa0464ef2b608
+GitCommit: 48c7ca0ae7473f3127650f45f21e8ea85d7bb4d2
 Directory: 5.7
 
 Tags: 5.6.36, 5.6
-GitCommit: 6c952606d78b4b0e1041ad91514aa0464ef2b608
+GitCommit: 48c7ca0ae7473f3127650f45f21e8ea85d7bb4d2
 Directory: 5.6
 
 Tags: 5.5.55, 5.5
-GitCommit: 6c952606d78b4b0e1041ad91514aa0464ef2b608
+GitCommit: 48c7ca0ae7473f3127650f45f21e8ea85d7bb4d2
 Directory: 5.5