force-flush file streams in patcher store

Author: goaaats

src/XIVLauncher.Common/Patching/ZiPatch/Util/SqexFileStreamStore.cs

@@ -38,7 +38,11 @@ public void CloseStream(string path)
         public void Dispose()
         {
             foreach (var stream in _streams.Values)
+            {
+                stream.Flush(true);
                 stream.Dispose();
+            }
+
             this._streams.Clear();
         }
     }