[FLINK-22104][sql-client] Fix unstable SqlClientTest.testExecuteSqlFile

[fsk119]

What is the purpose of the change

The actual line is
LOAD MODULE Load a module. Syntax: 'LOAD MODULE <name> [WITH ('<key1>' =Q '<value1>' [, '<key2>' = '<value2>', ...])];'
But the expected line is
LOAD MODULE Load a module. Syntax: 'LOAD MODULE <name> [WITH ('<key1>' = '<value1>' [, '<key2>' = '<value2>', ...])];'
The main problem is the we hijack the System.in and the client echo the input to the output.
However, we don't need QUIT in this case. Therefore, we just use setIn where we needs.

Verifying this change

This change is a trivial rework / code cleanup without any test coverage.

Documentation

• Does this pull request introduce a new feature? (yes / no)
• If yes, how is the feature documented? (not applicable / docs / JavaDocs / not documented)

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Automated Checks

Last check on commit 556c5fe (Fri May 28 09:10:08 UTC 2021)

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[wuchong]

LGTM.

[wuchong]

The build hangs on sql client tests. Please have a check.

[wuchong]

LGTM.