mysql client clear text authentication password should end with a 0x0…

[BillyYccc]

…0 byte

Signed-off-by: Billy Yuan [email protected]

Motivation:

fixes https://github.com/eclipse-vertx/vertx-sql-client/issues/1215

Conformance:

You should have signed the Eclipse Contributor Agreement as explained in https://github.com/eclipse/vert.x/blob/master/CONTRIBUTING.md Please also make sure you adhere to the code style guidelines: https://github.com/vert-x3/wiki/wiki/Vert.x-code-style-guidelines