Update mysql Docker tag to v5.7

5 jobs for renovate/mysql-5.x in 57 seconds (queued for 40 seconds)
Name Stage Failure
start-UoW Start
debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
debug1: channel 0: free: client-session, nchannels 1
debug1: fd 0 clearing O_NONBLOCK
debug1: fd 2 clearing O_NONBLOCK
Transferred: sent 22532, received 3880 bytes, in 0.8 seconds
Bytes per second: sent 26801.8, received 4615.3
debug1: Exit status 0
Cleaning up project directory and file based variables
ERROR: Job failed: exit code 1