Fix count of skipped test of basebackup on Windows

Commit 920a5e500a add tests which should be
skipped on Windows boxes, but patch doesn't contain right count of them.

David Steel

src/bin/pg_basebackup/t/010_pg_basebackup.pl

@@ -183,7 +183,7 @@ unlink "$pgdata/$superlongname";
 # skip on Windows.
 SKIP:
 {
-	skip "symlinks not supported on Windows", 15 if ($windows_os);
+	skip "symlinks not supported on Windows", 17 if ($windows_os);
 
 	# Move pg_replslot out of $pgdata and create a symlink to it.
 	$node->stop;