revert pubBlobByKey() change

examples/companion_radio/DataStore.cpp

@@ -515,7 +515,7 @@ uint8_t DataStore::getBlobByKey(const uint8_t key[], int key_len, uint8_t dest_b
 bool DataStore::putBlobByKey(const uint8_t key[], int key_len, const uint8_t src_buf[], uint8_t len) {
   if (len < PUB_KEY_SIZE+4+SIGNATURE_SIZE || len > MAX_ADVERT_PKT_LEN) return false;
   checkAdvBlobFile();
-  File file = openWrite(_getContactsChannelsFS(), "/adv_blobs");
+  File file = _getContactsChannelsFS()->open("/adv_blobs", FILE_O_WRITE);
   if (file) {
     uint32_t pos = 0, found_pos = 0;
     uint32_t min_timestamp = 0xFFFFFFFF;