Make 013_crash_recovery.pl work on repeated runs

If the keyring from a previous run is still present, the test fails.

Author: Anders Åstrand

contrib/pg_tde/t/013_crash_recovery.pl

@@ -7,6 +7,9 @@
 use lib 't';
 use pgtde;
 
+# ensure we start with a clean key provider file
+unlink('/tmp/crash_recovery.per');
+
 PGTDE::setup_files_dir(basename($0));
 
 my $node = PostgreSQL::Test::Cluster->new('main');