erp5_web_mynij_search: Add default mynij config file

bt5/erp5_web_mynij_search/PathTemplateItem/web_page_module/mynij-config_json.js

+{
+  "rtcConfig": {
+    "iceServers": [
+      {
+        "urls": [
+          "stun:turn.api.nexedi.net:3478",
+          "stun:stun.l.google.com:19302"
+        ]
+      }
+    ]
+  },
+  "proxies": {
+    "urls": [
+        "https://softinst65443.host.vifib.net/proxy"
+    ]
+  }
+}
\ No newline at end of file