* #9847: check pointer before using it

daemon/src/sip/sipvoiplink.cpp

@@ -1551,6 +1551,11 @@ void update_contact_header(pjsip_regc_cbparam *param, SIPAccount *account)
 
 void registration_cb(pjsip_regc_cbparam *param)
 {
+    if (param == NULL) {
+        ERROR("SipVoipLink: registration callback parameter is NULL");
+        return;
+    }
+
     SIPAccount *account = static_cast<SIPAccount *>(param->token);
 
     if (account == NULL) {
@@ -1558,11 +1563,6 @@ void registration_cb(pjsip_regc_cbparam *param)
         return;
     }
 
-    if (param == NULL) {
-        ERROR("SipVoipLink: registration callback parameter is NULL");
-        return;
-    }
-
     if (account->isContactUpdateEnabled())
         update_contact_header(param, account);