use mysql5.7 again

Author: fffunke

test/pkg/source/mysqltest/mysql_test.go

@@ -37,7 +37,7 @@ const tableName = "testTable"
 // mysql and psql are a bit picky when it comes to localhost, use ip instead
 const hostName = "127.0.0.1"
 const logString = "ready for connections"
-const mysqlImage = "docker.io/bitnami/mysql:8"
+const mysqlImage = "docker.io/bitnami/mysql:5.7"
 
 type MySQLDumpAndRestoreTestSuite struct {
 	suite.Suite