erlang-p1_mysql: Update to 1.0.18

upstream changes:
-----------------
Version 1.0.18
  o Update copyright year to 2021
  o add_mysql_conn always returns success, except if crashes
  o Database is always 'none', as noticed by Dialyzer
  o Data is always binary, as noticed by Dialyzer

Version 1.0.17
  o Update travis config

Version 1.0.15
  o Fix warnings

Version 1.0.14
  o Add abilty to use ssl connections

Version 1.0.13
  o Update copyright year

Version 1.0.12
  o Properly handle decoding of number of returned fields when there is more than 128 of them.

Version 1.0.11
  o Handle close even in do_recv, this fixes potential connection being stuck after timeout

Version 1.0.10
  o Make socket close always lead to terminating p1_mysql_conn

Version 1.0.9
  o Add contribution guide
  o Don't log errors on shutdown

Version 1.0.8
  o Add support for mysql8 and cache_sha2_password authentication

Version 1.0.7
  o Fix connection timeout handling

(triaxx)