pgsql: Fix issues in pg_rewind with --no-ensure-shutdown/--write-recove

Fix issues in pg_rewind with --no-ensure-shutdown/--write-recovery-conf

This fixes two issues with recent features added in pg_rewind:
- --dry-run should do nothing on the target directory, but 927474c
forgot to consider that for --write-recovery-conf.
- --no-ensure-shutdown was not actually working.  There is no test
coverage for this option yet, but a subsequent patch will add that.

Author: Alexey Kondratov
Discussion: https://postgr.es/m/7ca88204-3e0b-2f4c-c8af-acadc4b266e5@postgrespro.ru

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/6837632b758e0470a2692d9f8303e8aebd6fbd8f

Modified Files
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src/bin/pg_rewind/pg_rewind.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)