[update]更新群发功能

app/src/main/java/com/offcn/imclient/ui/ContactListFragment.java

@@ -77,9 +77,12 @@ public class ContactListFragment extends BaseFragment {
                         StringBuilder stringBuilder = new StringBuilder();
                         List<UserBean> tmpList = contactBean.getList();
                         if (!ValidateUtils.isEmpty(tmpList)) {
-                            for (UserBean bean : tmpList) {
-                                stringBuilder.append(bean.getUser_id());
-                                stringBuilder.append(",");
+                            for (int i = 0; i < tmpList.size(); i++) {
+                                UserBean tmp = tmpList.get(i);
+                                stringBuilder.append(tmp.getUser_id());
+                                if (i != tmpList.size() - 1) {
+                                    stringBuilder.append(",");
+                                }
                             }
                             toId = stringBuilder.toString();
                         }