pgsql: Unrevert "Force nodes for SSL tests to start in TCP mode"

Unrevert "Force nodes for SSL tests to start in TCP mode"

This reverts commit 8b03d743a85fed4930645382a219cc75bdf7ab73.

Release 12 required a little extra sauce to make it work, but this has
been tested now.

Branch
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REL_12_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/d1c30fd884b60c6f342e728df046cf2f701e79d7

Modified Files
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src/test/ssl/t/SSLServer.pm | 7 +++++++
1 file changed, 7 insertions(+)