pgsql: Drop server support for FE/BE protocol version 1.0.

Drop server support for FE/BE protocol version 1.0.

While this isn't a lot of code, it's been essentially untestable for
a very long time, because libpq doesn't support anything older than
protocol 2.0, and has not since release 6.3. There's no reason to
believe any other client-side code still uses that protocol, either.

Discussion: <2661(dot)1475849167(at)sss(dot)pgh(dot)pa(dot)us>

Branch
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master

Details
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http://git.postgresql.org/pg/commitdiff/2f1eaf87e868a1c42f2b159958623daa6a666de4

Modified Files
--------------
src/backend/access/common/printtup.c | 4 +---
src/backend/commands/copy.c | 28 ++--------------------------
src/backend/tcop/dest.c | 6 +++---
src/backend/tcop/postgres.c | 3 +--
src/include/libpq/pqcomm.h | 2 +-
5 files changed, 8 insertions(+), 35 deletions(-)