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/env/env_test.go

@@ -68,7 +68,6 @@ func Test_PrintVersion(t *testing.T) {
 				logger.EXPECT().Error(tc.commandErr).Do(func(err error) {
 					logged = err.Error()
 				}).Times(1)
-
 			} else {
 				logger.EXPECT().Info("%s version: %s", tc.program, tc.commandVersion).
 					Do(func(format, program, version string) {