allow to change UA uri in runtime (#425)

* UA: allow to change 'uri' in runtime

* expose UA.set in SIPUAHelper as setUAParam

Author: furmur

lib/src/sip_ua_helper.dart

@@ -404,6 +404,10 @@ class SIPUAHelper extends EventManager {
     return defaultOptions;
   }
 
+  bool setUAParam(String parameter, dynamic value) {
+    return _ua!.set(parameter, value);
+  }
+
   Message sendMessage(String target, String body,
       [Map<String, dynamic>? options, Map<String, dynamic>? params]) {
     return _ua!.sendMessage(target, body, options, params);

lib/src/ua.dart

@@ -435,6 +435,12 @@ class UA extends EventManager {
           break;
         }
 
+      case 'uri':
+        {
+          _configuration.uri = value;
+          break;
+        }
+
       default:
         logger.e('set() | cannot set "$parameter" parameter in runtime');