updating getEnv function log (#156)

src/webserver.go

@@ -280,11 +280,17 @@ func isNil(i interface{}) bool {
 	}
 	return false
 }
+
+// isEnvExist func - check if environment var is set
+func isEnvExist(key string) (ok bool) {
+	_, ok = os.LookupEnv(key)
+	return
+}
 */
 
 // getEnv func - read an environment or return a default value
 func getEnv(key string, defaultVal string) string {
-	if value, exists := os.LookupEnv(key); exists {
+	if value, exists := os.LookupEnv(key); exists && value != "" {
 		return value
 	}
 	return defaultVal