Ignore exceptions while saving exitstatus

Since it could break normal job closing and bring duplicated executions.

lib/TheSchwartz/Job.pm

@@ -183,7 +183,27 @@ sub set_exit_status {
     }
 
     my $driver = $job->driver;
-    $driver->insert($status);
+    eval {
+        $driver->insert($status);
+    };
+    if ( my $e = $@ ) {
+        my $jobid = $job->jobid;
+        if ( $e =~ /Failed to execute INSERT INTO exitstatus/
+            && $e =~ /Duplicate entry/ ) {
+            # Already saved exitstatus, it means this job was
+            # already executed.
+            # Ignore this...
+            print STDERR "Got duplicated entry for exitstatus($exit) of job $jobid: $e\n";
+            print STDERR Dumper $job;
+        }
+        else {
+            print STDERR "Got an error when saving exitstatus($exit) of job $jobid: $e\n";
+            print STDERR Dumper $job;
+        }
+
+        # Anyway, we can't do anything here. Just ignore the exception.
+    }
+
 
     # and let's lazily clean some exitstatus while we're here.  but
     # rather than doing this query all the time, we do it 1/nth of the