Error message is incorrect

Describe the bug
If the binlog backup fails, the following message is added to the warning:

"warnings": [
  "failed to backup binary logs: failed to take a full dump: exit status 1"
],

This is a binlog backup failure, not full dump failure.

moco/backup/backup.go

Lines 363 to 365 in bf0d148

    
           if err := op.DumpBinlog(ctx, binlogDir, binlogName, lastBackup.GTIDSet); err != nil { 
        
           	return fmt.Errorf("failed to take a full dump: %w", err) 
        
           }

Expected behavior
Outputs binlog backup failed.

	if err := op.DumpBinlog(ctx, binlogDir, binlogName, lastBackup.GTIDSet); err != nil {
	return fmt.Errorf("failed to take a full dump: %w", err)
	}