pgsql: Fix failure-to-compile-standalone in ecpg's dt.h.

Fix failure-to-compile-standalone in ecpg's dt.h.

This has to have <time.h>, or the references to "struct tm" don't
mean what they should.

We have some other recently-introduced issues of the same ilk,
but this one seems old.  No backpatch though, as it's only a
latent problem for most purposes.

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/5c66e99178c2f72042034cceb6bc4902650a2608

Modified Files
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src/interfaces/ecpg/pgtypeslib/dt.h | 2 ++
1 file changed, 2 insertions(+)