Golangcilint in build pipeline and fix lint errors

- Fix bad permissions bits for files
- VPNSP is 'private internet access' instead of 'pia' (retro compatible)
- Check errors of deferred unsetEnv functions in params package
-  Other lint errors fixing and code simplifications

internal/dns/wait.go

@@ -14,7 +14,7 @@ func (c *configurator) WaitForUnbound() (err error) {
 			return nil
 		}
 		c.logger.Warn("could not resolve %s (try %d of %d): %s", hostToResolve, try, maxTries, err)
-		time.Sleep(time.Duration(maxTries * 50 * time.Millisecond))
+		time.Sleep(maxTries * 50 * time.Millisecond)
 	}
 	return fmt.Errorf("Unbound does not seem to be working after %d tries", maxTries)
 }