DBAL-997: [GH-685] Update MasterSlaveConnection.php

[doctrinebot]

Jira issue originally created by user @doctrinebot:

This issue is created automatically through a Github pull request on behalf of ChristopheBoucaut:

Url: #685

Message:

If you use close method just before connect method, $this->_conn is unset and we have got an error php.

[doctrinebot]

• depends on DBAL-1003: [GH-688] Fixed closing a connection
• depends on DBAL-1008: [GH-691] Add test case for #688

[doctrinebot]

Comment created by @doctrinebot:

A related Github Pull-Request [GH-685] was closed:
#685

[doctrinebot]

Comment created by @doctrinebot:

A related Github Pull-Request [GH-685] was assigned:
#685

[doctrinebot]

Comment created by @Ocramius:

Incorrect fix, as it fixes a symptom rather than the issue itself

[doctrinebot]

Issue was closed with resolution "Invalid"

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.