Merge branch '5402-master-contacts_sync_npe' into 'master'

AccountManager: properly check for null or empty accesstoken

See merge request !44

app/src/main/java/foundation/e/accountmanager/syncadapter/ContactsSyncManager.kt

@@ -442,7 +442,7 @@ class ContactsSyncManager(
                             .get()
                             .url(httpUrl)
 
-                if (accessToken!!.isNotEmpty()) {
+                if (!accessToken.isNullOrEmpty()) {
 			requestBuilder.header("Authorization", "Bearer $accessToken")
                     }