send unsent messages after first sync

src/main.js

@@ -76,6 +76,7 @@ export default async function main(container) {
         if (needsInitialSync) {
             showSession(container, session, sync);
         }
+        session.notifyNetworkAvailable();
     } catch(err) {
         console.error(`${err.message}:\n${err.stack}`);
     }

src/matrix/room/room.js

@@ -42,6 +42,10 @@ export default class Room extends EventEmitter {
         }
 	}
 
+    resumeSending() {
+        this._sendQueue.resumeSending();
+    }
+
 	load(summary, txn) {
 		this._summary.load(summary);
 		return this._syncWriter.load(txn);

src/matrix/session.js

@@ -38,6 +38,12 @@ export default class Session {
         }));
     }
 
+    notifyNetworkAvailable() {
+        for (const room of this._rooms) {
+            room.resumeSending();
+        }
+    }
+
     async _getPendingEventsByRoom(txn) {
         const pendingEvents = await txn.pendingEvents.getAll();
         return pendingEvents.reduce((groups, pe) => {