Use asyncio.gather to propogate exceptions

electrumx/server/mempool.py

@@ -168,7 +168,7 @@ class MemPool(object):
                                        (hashes, all_hashes, touched))
                 for hashes in chunks(new_hashes, 2000)]
         if jobs:
-            await asyncio.wait(jobs)
+            await asyncio.gather(*jobs)
             tx_map = {}
             utxo_map = {}
             for job in jobs:

electrumx/server/peers.py

@@ -281,7 +281,7 @@ class PeerManager(object):
             self._send_server_features(session, peer, timeout),
             self._send_peers_subscribe(session, peer, timeout)
         )]
-        await asyncio.wait(jobs)
+        await asyncio.gather(*jobs)
 
     async def _send_headers_subscribe(self, session, peer, timeout, ptuple):
         request = session.send_request('blockchain.headers.subscribe',