[REFACTOR] Fix search not null issue on search_kegiatan

lib/repository/kegiatan_repository.dart

@@ -33,7 +33,7 @@ class KegiatanRepository implements BaseKegiatanRepository {
   @override
   Future<dynamic> fetchKegiatanSearch(String search, String sortConfig) async {
     var url = '/informasi-fasilitas/lokasi/list-kegiatan-by-$sortConfig';
-    if(search != null){
+    if(search != null && search!=''){
       url += '/$search';
     }
     final response = await _network.get(url: url, isLogin: false);