truststore: check if profile is a directory before joining cert*.db (FiloSottile#33)

Author: ansemjo

truststore_nss.go

@@ -97,6 +97,9 @@ func (m *mkcert) forEachNSSProfile(f func(profile string)) (found int) {
 		return
 	}
 	for _, profile := range profiles {
+		if stat, err := os.Stat(profile); err != nil || !stat.IsDir() {
+			continue
+		}
 		if _, err := os.Stat(filepath.Join(profile, "cert8.db")); !os.IsNotExist(err) {
 			f("dbm:" + profile)
 			found++